docs-site/docs/configure/admin-panel.md

@@ -41,7 +41,7 @@ When a non-admin user picks a shared provider in **Settings → TTS Provider**:
 
 - The API key / base URL fields are hidden — those credentials never leave the server.
 - The TTS request still goes through the user's browser, but the server replaces the slug with the matching admin row's decrypted key and base URL before calling the upstream provider.
-- TTS credentials are resolved only from admin-managed shared providers and are never accepted from client request headers.
+- The user's per-request `x-openai-key` / `x-openai-base-url` headers are ignored for shared slugs.
 
 Whether users can supply their own personal built-in provider keys is controlled by the site feature `restrictUserApiKeys`:
 

docs-site/docs/reference/stack.md

@@ -20,7 +20,7 @@ title: Stack
 - Interactions: `react-dnd`, `react-dropzone`
 - Server state: [TanStack Query](https://tanstack.com/query) (React Query v5)
 - Authentication: [Better Auth](https://www.better-auth.com/) client SDK
-- Browser blob performance cache: Cache Storage (evictable; never authoritative)
+- Local storage/cache: [Dexie.js](https://dexie.org/) (IndexedDB)
 - Audio playback: [Howler.js](https://howlerjs.com/)
 - Notifications: `react-hot-toast`
 - Document rendering:

eslint.config.mjs

@@ -29,6 +29,7 @@ const UI_ARCHITECTURE_FILES = [
   "src/components/doclist/**/*.{ts,tsx}",
   "src/components/documents/DocumentUploader.tsx",
   "src/components/documents/DocumentSelectionModal.tsx",
+  "src/components/documents/DexieMigrationModal.tsx",
   "src/components/documents/ZoomControl.tsx",
   "src/components/player/**/*.{ts,tsx}",
   "src/components/reader/**/*.{ts,tsx}",

package.json

@@ -54,6 +54,8 @@
     "cmpstr": "^3.3.0",
     "compromise": "^14.15.1",
     "core-js": "^3.49.0",
+    "dexie": "^4.4.3",
+    "dexie-react-hooks": "^4.4.0",
     "dotenv": "^17.4.2",
     "drizzle-orm": "^0.45.2",
     "epubjs": "^0.3.93",
@@ -100,8 +102,8 @@
     "drizzle-kit": "^0.31.10",
     "eslint": "^9.39.4",
     "eslint-config-next": "^15.5.19",
-    "openapi-typescript": "^7.10.1",
     "postcss": "^8.5.15",
+    "openapi-typescript": "^7.10.1",
     "tailwindcss": "^3.4.19",
     "typescript": "^5.9.3",
     "vitest": "^4.1.8"

packages/compute-worker/tests/fixtures/fake-control-plane.ts

@@ -19,7 +19,7 @@ export class FakeControlPlane {
   private readonly artifactKeys = new Set<string>();
   private nextOpId = 1;
 
-  readonly deps = {
+  readonly deps: ComputeWorkerRouteDeps = {
     orchestrator: {
       enqueueOrReuse: async (request) => this.enqueueOrReuse(request),
       markRunning: async (input) => this.updateState(input.opId, {
@@ -75,7 +75,7 @@ export class FakeControlPlane {
       },
     },
     artifactExists: async (key) => this.artifactKeys.has(key),
-  } satisfies ComputeWorkerRouteDeps;
+  };
 
   seedState(state: ComputeState): void {
     this.stateByOpId.set(state.opId, state);

packages/compute-worker/tests/unit/orphan-recovery.test.ts

@@ -24,8 +24,8 @@ describe('orphan recovery', () => {
     });
 
     const firstSweep = await recoverOrphanedOperations({
-      operationStateStore: fake.deps.operationStateStore,
-      orchestrator: fake.deps.orchestrator,
+      operationStateStore: fake.deps.operationStateStore!,
+      orchestrator: fake.deps.orchestrator!,
       whisperTimeoutMs: 30_000,
       pdfTimeoutMs: 300_000,
       opStaleMs: 1_800_000,
@@ -38,8 +38,8 @@ describe('orphan recovery', () => {
     vi.advanceTimersByTime(31_000);
 
     const secondSweep = await recoverOrphanedOperations({
-      operationStateStore: fake.deps.operationStateStore,
-      orchestrator: fake.deps.orchestrator,
+      operationStateStore: fake.deps.operationStateStore!,
+      orchestrator: fake.deps.orchestrator!,
       whisperTimeoutMs: 30_000,
       pdfTimeoutMs: 300_000,
       opStaleMs: 1_800_000,

packages/database/migrations/postgres/0012_user_additions.sql

@@ -1,26 +0,0 @@
-CREATE TABLE "user_folders" (
-	"id" text NOT NULL,
-	"user_id" text NOT NULL,
-	"name" text NOT NULL,
-	"position" integer DEFAULT 0 NOT NULL,
-	"created_at" bigint DEFAULT (extract(epoch from now()) * 1000)::bigint,
-	"updated_at" bigint DEFAULT (extract(epoch from now()) * 1000)::bigint,
-	CONSTRAINT "user_folders_id_user_id_pk" PRIMARY KEY("id","user_id")
-);
---> statement-breakpoint
-CREATE TABLE "user_onboarding" (
-	"user_id" text PRIMARY KEY NOT NULL,
-	"privacy_accepted_at_ms" bigint,
-	"last_seen_app_version" text,
-	"created_at" bigint DEFAULT (extract(epoch from now()) * 1000)::bigint,
-	"updated_at" bigint DEFAULT (extract(epoch from now()) * 1000)::bigint
-);
---> statement-breakpoint
-ALTER TABLE "documents" ADD COLUMN "folder_id" text;--> statement-breakpoint
-ALTER TABLE "documents" ADD COLUMN "recently_opened_at" bigint;--> statement-breakpoint
-ALTER TABLE "user_folders" ADD CONSTRAINT "user_folders_user_id_user_id_fk" FOREIGN KEY ("user_id") REFERENCES "public"."user"("id") ON DELETE cascade ON UPDATE no action;--> statement-breakpoint
-ALTER TABLE "user_onboarding" ADD CONSTRAINT "user_onboarding_user_id_user_id_fk" FOREIGN KEY ("user_id") REFERENCES "public"."user"("id") ON DELETE cascade ON UPDATE no action;--> statement-breakpoint
-CREATE INDEX "idx_user_folders_user_position" ON "user_folders" USING btree ("user_id","position");--> statement-breakpoint
-ALTER TABLE "documents" ADD CONSTRAINT "documents_folder_id_user_id_user_folders_id_user_id_fk" FOREIGN KEY ("folder_id","user_id") REFERENCES "public"."user_folders"("id","user_id") ON DELETE no action ON UPDATE no action;--> statement-breakpoint
-CREATE INDEX "idx_documents_user_id_folder" ON "documents" USING btree ("user_id","folder_id");--> statement-breakpoint
-CREATE INDEX "idx_documents_user_id_recently_opened" ON "documents" USING btree ("user_id","recently_opened_at");

packages/database/migrations/postgres/meta/_journal.json

@@ -85,13 +85,6 @@
       "when": 1780851107819,
       "tag": "0011_scheduled-tasks",
       "breakpoints": true
-    },
-    {
-      "idx": 12,
-      "version": "7",
-      "when": 1781466220153,
-      "tag": "0012_user_additions",
-      "breakpoints": true
     }
   ]
 }

packages/database/migrations/sqlite/0012_user_additions.sql

@@ -1,46 +0,0 @@
-CREATE TABLE `user_folders` (
-	`id` text NOT NULL,
-	`user_id` text NOT NULL,
-	`name` text NOT NULL,
-	`position` integer DEFAULT 0 NOT NULL,
-	`created_at` integer DEFAULT (cast(unixepoch('subsecond') * 1000 as integer)),
-	`updated_at` integer DEFAULT (cast(unixepoch('subsecond') * 1000 as integer)),
-	PRIMARY KEY(`id`, `user_id`),
-	FOREIGN KEY (`user_id`) REFERENCES `user`(`id`) ON UPDATE no action ON DELETE cascade
-);
---> statement-breakpoint
-CREATE INDEX `idx_user_folders_user_position` ON `user_folders` (`user_id`,`position`);--> statement-breakpoint
-CREATE TABLE `user_onboarding` (
-	`user_id` text PRIMARY KEY NOT NULL,
-	`privacy_accepted_at_ms` integer,
-	`last_seen_app_version` text,
-	`created_at` integer DEFAULT (cast(unixepoch('subsecond') * 1000 as integer)),
-	`updated_at` integer DEFAULT (cast(unixepoch('subsecond') * 1000 as integer)),
-	FOREIGN KEY (`user_id`) REFERENCES `user`(`id`) ON UPDATE no action ON DELETE cascade
-);
---> statement-breakpoint
-PRAGMA foreign_keys=OFF;--> statement-breakpoint
-CREATE TABLE `__new_documents` (
-	`id` text NOT NULL,
-	`user_id` text NOT NULL,
-	`name` text NOT NULL,
-	`type` text NOT NULL,
-	`size` integer NOT NULL,
-	`last_modified` integer NOT NULL,
-	`file_path` text NOT NULL,
-	`folder_id` text,
-	`recently_opened_at` integer,
-	`created_at` integer DEFAULT (cast(unixepoch('subsecond') * 1000 as integer)),
-	PRIMARY KEY(`id`, `user_id`),
-	FOREIGN KEY (`user_id`) REFERENCES `user`(`id`) ON UPDATE no action ON DELETE cascade,
-	FOREIGN KEY (`folder_id`,`user_id`) REFERENCES `user_folders`(`id`,`user_id`) ON UPDATE no action ON DELETE no action
-);
---> statement-breakpoint
-INSERT INTO `__new_documents`("id", "user_id", "name", "type", "size", "last_modified", "file_path", "folder_id", "recently_opened_at", "created_at") SELECT "id", "user_id", "name", "type", "size", "last_modified", "file_path", NULL, NULL, "created_at" FROM `documents`;--> statement-breakpoint
-DROP TABLE `documents`;--> statement-breakpoint
-ALTER TABLE `__new_documents` RENAME TO `documents`;--> statement-breakpoint
-PRAGMA foreign_keys=ON;--> statement-breakpoint
-CREATE INDEX `idx_documents_user_id` ON `documents` (`user_id`);--> statement-breakpoint
-CREATE INDEX `idx_documents_user_id_last_modified` ON `documents` (`user_id`,`last_modified`);--> statement-breakpoint
-CREATE INDEX `idx_documents_user_id_folder` ON `documents` (`user_id`,`folder_id`);--> statement-breakpoint
-CREATE INDEX `idx_documents_user_id_recently_opened` ON `documents` (`user_id`,`recently_opened_at`);

packages/database/migrations/sqlite/meta/_journal.json

@@ -85,13 +85,6 @@
       "when": 1780851107505,
       "tag": "0011_scheduled-tasks",
       "breakpoints": true
-    },
-    {
-      "idx": 12,
-      "version": "6",
-      "when": 1781466219864,
-      "tag": "0012_user_additions",
-      "breakpoints": true
     }
   ]
 }

packages/database/src/schema.ts

@@ -7,13 +7,11 @@ const usePostgres = !!process.env.POSTGRES_URL;
 // and are NOT part of the Drizzle schema. Only app-specific tables are exported here.
 
 export const documents = usePostgres ? postgresSchema.documents : sqliteSchema.documents;
-export const userFolders = usePostgres ? postgresSchema.userFolders : sqliteSchema.userFolders;
 export const audiobooks = usePostgres ? postgresSchema.audiobooks : sqliteSchema.audiobooks;
 export const audiobookChapters = usePostgres ? postgresSchema.audiobookChapters : sqliteSchema.audiobookChapters;
 export const userTtsChars = usePostgres ? postgresSchema.userTtsChars : sqliteSchema.userTtsChars;
 export const userJobEvents = usePostgres ? postgresSchema.userJobEvents : sqliteSchema.userJobEvents;
 export const userPreferences = usePostgres ? postgresSchema.userPreferences : sqliteSchema.userPreferences;
-export const userOnboarding = usePostgres ? postgresSchema.userOnboarding : sqliteSchema.userOnboarding;
 export const documentSettings = usePostgres ? postgresSchema.documentSettings : sqliteSchema.documentSettings;
 export const userDocumentProgress = usePostgres ? postgresSchema.userDocumentProgress : sqliteSchema.userDocumentProgress;
 export const documentPreviews = usePostgres ? postgresSchema.documentPreviews : sqliteSchema.documentPreviews;

packages/database/src/schema_postgres.ts

@@ -4,18 +4,6 @@ import { user } from './schema_auth_postgres';
 
 const PG_NOW_MS = sql`(extract(epoch from now()) * 1000)::bigint`;
 
-export const userFolders = pgTable('user_folders', {
-  id: text('id').notNull(),
-  userId: text('user_id').notNull().references(() => user.id, { onDelete: 'cascade' }),
-  name: text('name').notNull(),
-  position: integer('position').notNull().default(0),
-  createdAt: bigint('created_at', { mode: 'number' }).default(PG_NOW_MS),
-  updatedAt: bigint('updated_at', { mode: 'number' }).default(PG_NOW_MS),
-}, (table) => [
-  primaryKey({ columns: [table.id, table.userId] }),
-  index('idx_user_folders_user_position').on(table.userId, table.position),
-]);
-
 export const documents = pgTable('documents', {
   id: text('id').notNull(),
   userId: text('user_id').notNull().references(() => user.id, { onDelete: 'cascade' }),
@@ -24,19 +12,11 @@ export const documents = pgTable('documents', {
   size: bigint('size', { mode: 'number' }).notNull(),
   lastModified: bigint('last_modified', { mode: 'number' }).notNull(),
   filePath: text('file_path').notNull(),
-  folderId: text('folder_id'),
-  recentlyOpenedAt: bigint('recently_opened_at', { mode: 'number' }),
   createdAt: bigint('created_at', { mode: 'number' }).default(PG_NOW_MS),
 }, (table) => [
   primaryKey({ columns: [table.id, table.userId] }),
-  foreignKey({
-    columns: [table.folderId, table.userId],
-    foreignColumns: [userFolders.id, userFolders.userId],
-  }),
   index('idx_documents_user_id').on(table.userId),
   index('idx_documents_user_id_last_modified').on(table.userId, table.lastModified),
-  index('idx_documents_user_id_folder').on(table.userId, table.folderId),
-  index('idx_documents_user_id_recently_opened').on(table.userId, table.recentlyOpenedAt),
 ]);
 
 export const audiobooks = pgTable('audiobooks', {
@@ -109,14 +89,6 @@ export const userPreferences = pgTable('user_preferences', {
   updatedAt: bigint('updated_at', { mode: 'number' }).default(PG_NOW_MS),
 });
 
-export const userOnboarding = pgTable('user_onboarding', {
-  userId: text('user_id').primaryKey().references(() => user.id, { onDelete: 'cascade' }),
-  privacyAcceptedAtMs: bigint('privacy_accepted_at_ms', { mode: 'number' }),
-  lastSeenAppVersion: text('last_seen_app_version'),
-  createdAt: bigint('created_at', { mode: 'number' }).default(PG_NOW_MS),
-  updatedAt: bigint('updated_at', { mode: 'number' }).default(PG_NOW_MS),
-});
-
 export const documentSettings = pgTable('document_settings', {
   documentId: text('document_id').notNull(),
   userId: text('user_id').notNull().references(() => user.id, { onDelete: 'cascade' }),

packages/database/src/schema_sqlite.ts

@@ -4,18 +4,6 @@ import { user } from './schema_auth_sqlite';
 
 const SQLITE_NOW_MS = sql`(cast(unixepoch('subsecond') * 1000 as integer))`;
 
-export const userFolders = sqliteTable('user_folders', {
-  id: text('id').notNull(),
-  userId: text('user_id').notNull().references(() => user.id, { onDelete: 'cascade' }),
-  name: text('name').notNull(),
-  position: integer('position').notNull().default(0),
-  createdAt: integer('created_at').default(SQLITE_NOW_MS),
-  updatedAt: integer('updated_at').default(SQLITE_NOW_MS),
-}, (table) => [
-  primaryKey({ columns: [table.id, table.userId] }),
-  index('idx_user_folders_user_position').on(table.userId, table.position),
-]);
-
 export const documents = sqliteTable('documents', {
   id: text('id').notNull(),
   userId: text('user_id').notNull().references(() => user.id, { onDelete: 'cascade' }),
@@ -24,19 +12,11 @@ export const documents = sqliteTable('documents', {
   size: integer('size').notNull(),
   lastModified: integer('last_modified').notNull(),
   filePath: text('file_path').notNull(),
-  folderId: text('folder_id'),
-  recentlyOpenedAt: integer('recently_opened_at'),
   createdAt: integer('created_at').default(SQLITE_NOW_MS),
 }, (table) => [
   primaryKey({ columns: [table.id, table.userId] }),
-  foreignKey({
-    columns: [table.folderId, table.userId],
-    foreignColumns: [userFolders.id, userFolders.userId],
-  }),
   index('idx_documents_user_id').on(table.userId),
   index('idx_documents_user_id_last_modified').on(table.userId, table.lastModified),
-  index('idx_documents_user_id_folder').on(table.userId, table.folderId),
-  index('idx_documents_user_id_recently_opened').on(table.userId, table.recentlyOpenedAt),
 ]);
 
 export const audiobooks = sqliteTable('audiobooks', {
@@ -109,14 +89,6 @@ export const userPreferences = sqliteTable('user_preferences', {
   updatedAt: integer('updated_at').default(SQLITE_NOW_MS),
 });
 
-export const userOnboarding = sqliteTable('user_onboarding', {
-  userId: text('user_id').primaryKey().references(() => user.id, { onDelete: 'cascade' }),
-  privacyAcceptedAtMs: integer('privacy_accepted_at_ms'),
-  lastSeenAppVersion: text('last_seen_app_version'),
-  createdAt: integer('created_at').default(SQLITE_NOW_MS),
-  updatedAt: integer('updated_at').default(SQLITE_NOW_MS),
-});
-
 export const documentSettings = sqliteTable('document_settings', {
   documentId: text('document_id').notNull(),
   userId: text('user_id').notNull().references(() => user.id, { onDelete: 'cascade' }),

pnpm-lock.yaml

@@ -59,6 +59,12 @@ importers:
       core-js:
         specifier: ^3.49.0
         version: 3.49.0
+      dexie:
+        specifier: ^4.4.3
+        version: 4.4.3
+      dexie-react-hooks:
+        specifier: ^4.4.0
+        version: 4.4.0(dexie@4.4.3)(react@19.2.7)
       dotenv:
         specifier: ^17.4.2
         version: 17.4.2
@@ -2600,6 +2606,15 @@ packages:
   devlop@1.1.0:
     resolution: {integrity: sha512-RWmIqhcFf1lRYBvNmr7qTNuyCt/7/ns2jbpp1+PalgE/rDQcBT0fioSMUpJ93irlUhC5hrg4cYqe6U+0ImW0rA==}
 
+  dexie-react-hooks@4.4.0:
+    resolution: {integrity: sha512-ObLXBS5+4BJU8vtSvBx6b9fY6zZYgniAtwxzjCHsUQadgbqYN6935X2/1TWw4Rf2N1aZV1io5/ziox4vKuxABA==}
+    peerDependencies:
+      dexie: '>=4.2.0-alpha.1 <5.0.0'
+      react: '>=16'
+
+  dexie@4.4.3:
+    resolution: {integrity: sha512-N+3IGQ3HPlyO2YAkntGAwitm42BpBGV86MttzUMiRzWLa4NGh0pltVRcUVF4ybL/OnXjCrr9k7SDPIKkFYP2Lg==}
+
   didyoumean@1.2.2:
     resolution: {integrity: sha512-gxtyfqMg7GKyhQmb056K7M3xszy/myH8w+B4RT+QXBQsvAOdc3XymqDDPHx1BgPgsdAA5SIifona89YtRATDzw==}
 
@@ -7074,6 +7089,13 @@ snapshots:
     dependencies:
       dequal: 2.0.3
 
+  dexie-react-hooks@4.4.0(dexie@4.4.3)(react@19.2.7):
+    dependencies:
+      dexie: 4.4.3
+      react: 19.2.7
+
+  dexie@4.4.3: {}
+
   didyoumean@1.2.2: {}
 
   dlv@1.1.3: {}

src/app/(app)/epub/[id]/page.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useParams } from "next/navigation";
+import { useParams, useRouter } from "next/navigation";
 import { useCallback, useEffect, useRef, useState } from 'react';
 import { DocumentSkeleton } from '@/components/documents/DocumentSkeleton';
 import { EPUBViewer } from '@/components/views/EPUBViewer';
@@ -14,6 +14,7 @@ import { SegmentsSidebar } from '@/components/reader/SegmentsSidebar';
 import { AudiobookExportModal } from '@/components/AudiobookExportModal';
 import type { TTSAudiobookChapter } from '@/types/tts';
 import type { AudiobookGenerationSettings } from '@/types/client';
+import { resolveDocumentId } from '@/lib/client/dexie';
 import { RateLimitBanner } from '@/components/auth/RateLimitBanner';
 import { useAuthRateLimit } from '@/contexts/AuthRateLimitContext';
 import { useFeatureFlag } from '@/contexts/RuntimeConfigContext';
@@ -25,6 +26,7 @@ import { useEpubDocument } from './useEpubDocument';
 export default function EPUBPage() {
   const canExportAudiobook = useFeatureFlag('enableAudiobookExport');
   const { id } = useParams();
+  const router = useRouter();
   const routeDocumentId = typeof id === 'string' ? id : undefined;
   const epubState = useEpubDocument(routeDocumentId);
   const {
@@ -60,13 +62,19 @@ export default function EPUBPage() {
 
   const loadDocument = useCallback(async () => {
     console.log('Loading new epub (from page.tsx)');
+    let didRedirect = false;
     let startedLoad = false;
     try {
       if (!routeDocumentId) {
         setError('Document not found');
         return;
       }
-      const resolved = routeDocumentId;
+      const resolved = await resolveDocumentId(routeDocumentId);
+      if (resolved !== routeDocumentId) {
+        didRedirect = true;
+        router.replace(`/epub/${resolved}`);
+        return;
+      }
 
       if (loadedDocIdRef.current === resolved) {
         return;
@@ -87,11 +95,11 @@ export default function EPUBPage() {
       if (startedLoad) {
         inFlightDocIdRef.current = null;
       }
-      if (startedLoad) {
+      if (!didRedirect && startedLoad) {
         setIsLoading(false);
       }
     }
-  }, [routeDocumentId, setCurrentDocument, stop]);
+  }, [routeDocumentId, router, setCurrentDocument, stop]);
 
   useEffect(() => {
     if (!isLoading) return;

src/app/(app)/epub/[id]/useEpubDocument.ts

@@ -115,6 +115,8 @@ export function useEpubDocument(documentId?: string): EpubDocumentState {
   } = useTTS();
   // Configuration context to get TTS settings
   const {
+    apiKey,
+    baseUrl,
     providerRef,
     ttsSegmentMaxBlockLength,
     epubTheme,
@@ -193,7 +195,7 @@ export function useEpubDocument(documentId?: string): EpubDocumentState {
   }, [resetHighlightState, setCurrDocPages, stop]);
 
   /**
-   * Sets the current document based on its ID using server metadata and the browser blob cache.
+   * Sets the current document based on its ID by fetching from IndexedDB
    * @param {string} id - The unique identifier of the document
    * @throws {Error} When document data is empty or retrieval fails
    */
@@ -476,6 +478,8 @@ export function useEpubDocument(documentId?: string): EpubDocumentState {
   const { createFullAudioBook, regenerateChapter } = useEPUBAudiobook({
     bookRef,
     tocRef,
+    apiKey,
+    baseUrl,
     providerRef,
   });
 

src/app/(app)/html/[id]/page.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useParams } from "next/navigation";
+import { useParams, useRouter } from "next/navigation";
 import { useCallback, useEffect, useRef, useState } from 'react';
 import { DocumentSkeleton } from '@/components/documents/DocumentSkeleton';
 import { HTMLViewer } from '@/components/views/HTMLViewer';
@@ -9,6 +9,7 @@ import { RateLimitPauseButton } from '@/components/player/RateLimitPauseButton';
 import { Header } from '@/components/Header';
 import { useTTS } from "@/contexts/TTSContext";
 import TTSPlayer from '@/components/player/TTSPlayer';
+import { resolveDocumentId } from '@/lib/client/dexie';
 import { DocumentHeaderMenu } from '@/components/documents/DocumentHeaderMenu';
 import { SegmentsSidebar } from '@/components/reader/SegmentsSidebar';
 import { RateLimitBanner } from '@/components/auth/RateLimitBanner';
@@ -25,6 +26,7 @@ import { useHtmlDocument } from './useHtmlDocument';
 export default function HTMLPage() {
   const canExportAudiobook = useFeatureFlag('enableAudiobookExport');
   const { id } = useParams();
+  const router = useRouter();
   const routeDocumentId = typeof id === 'string' ? id : undefined;
   const htmlState = useHtmlDocument();
   const {
@@ -61,13 +63,19 @@ export default function HTMLPage() {
   const loadDocument = useCallback(async () => {
     if (!isLoading) return;
     console.log('Loading new HTML document (from page.tsx)');
+    let didRedirect = false;
     let startedLoad = false;
     try {
       if (!id) {
         setError('Document not found');
         return;
       }
-      const resolved = id as string;
+      const resolved = await resolveDocumentId(id as string);
+      if (resolved !== (id as string)) {
+        didRedirect = true;
+        router.replace(`/html/${resolved}`);
+        return;
+      }
 
       if (loadedDocIdRef.current === resolved) {
         return;
@@ -88,11 +96,11 @@ export default function HTMLPage() {
       if (startedLoad) {
         inFlightDocIdRef.current = null;
       }
-      if (startedLoad) {
+      if (!didRedirect && startedLoad) {
         setIsLoading(false);
       }
     }
-  }, [isLoading, id, setCurrentDocument, stop]);
+  }, [isLoading, id, router, setCurrentDocument, stop]);
 
   useEffect(() => {
     if (!isLoading) return;

src/app/(app)/html/[id]/useHtmlDocument.ts

@@ -66,6 +66,8 @@ function buildFullDocumentText(blocks: HtmlBlock[]): string {
 export function useHtmlDocument(): HtmlDocumentState {
   const { setText: setTTSText, stop, setIsEPUB } = useTTS();
   const {
+    apiKey,
+    baseUrl,
     providerRef,
     ttsSegmentMaxBlockLength,
   } = useConfig();
@@ -171,6 +173,8 @@ export function useHtmlDocument(): HtmlDocumentState {
       try {
         return await runAudiobookGeneration({
           adapter: audiobookAdapter,
+          apiKey,
+          baseUrl,
           defaultProvider: providerRef,
           onProgress,
           signal,
@@ -185,7 +189,7 @@ export function useHtmlDocument(): HtmlDocumentState {
         throw error;
       }
     },
-    [audiobookAdapter, providerRef],
+    [audiobookAdapter, apiKey, baseUrl, providerRef],
   );
 
   const regenerateChapter = useCallback(
@@ -204,6 +208,8 @@ export function useHtmlDocument(): HtmlDocumentState {
           bookId,
           format,
           signal,
+          apiKey,
+          baseUrl,
           defaultProvider: providerRef,
           settings,
           retryOptions,
@@ -216,7 +222,7 @@ export function useHtmlDocument(): HtmlDocumentState {
         throw error;
       }
     },
-    [audiobookAdapter, providerRef],
+    [audiobookAdapter, apiKey, baseUrl, providerRef],
   );
 
   return useMemo(

src/app/(app)/layout.tsx

@@ -34,7 +34,12 @@ export default function AppLayout({ children }: { children: ReactNode }) {
       allowAnonymousAuthSessions={allowAnonymousAuthSessions}
       githubAuthEnabled={githubAuthEnabled}
     >
-      {/* Keep the preferences query/context mounted across library and reader navigation. */}
+      {/* ConfigProvider lives here, in the shared (app) layout, so it stays
+          mounted across library <-> reader navigation. Mounting it per-route
+          re-ran the Dexie/server hydration race on every navigation, causing
+          the reader to briefly use the admin-default provider until a full
+          page refresh. A single shared instance keeps the user's saved
+          provider hydrated the whole time. */}
       <ConfigProvider>
         <AppShell>
           <AppMain>{children}</AppMain>

src/app/(app)/pdf/[id]/page.tsx

@@ -14,6 +14,7 @@ import type { TTSAudiobookChapter } from '@/types/tts';
 import type { AudiobookGenerationSettings } from '@/types/client';
 import TTSPlayer from '@/components/player/TTSPlayer';
 import { RateLimitPauseButton } from '@/components/player/RateLimitPauseButton';
+import { resolveDocumentId } from '@/lib/client/dexie';
 import { RateLimitBanner } from '@/components/auth/RateLimitBanner';
 import { useAuthRateLimit } from '@/contexts/AuthRateLimitContext';
 import { useFeatureFlag } from '@/contexts/RuntimeConfigContext';
@@ -98,6 +99,7 @@ export default function PDFViewerPage() {
   const loadDocument = useCallback(async () => {
     if (!isLoading) return; // Prevent calls when not loading new doc
     console.log('Loading new document (from page.tsx)');
+    let didRedirect = false;
     let startedLoad = false;
     let loadSucceeded = false;
     try {
@@ -105,7 +107,12 @@ export default function PDFViewerPage() {
         setError('Document not found');
         return;
       }
-      const resolved = id as string;
+      const resolved = await resolveDocumentId(id as string);
+      if (resolved !== (id as string)) {
+        didRedirect = true;
+        router.replace(`/pdf/${resolved}`);
+        return;
+      }
 
       if (loadedDocIdRef.current === resolved) {
         return;
@@ -118,18 +125,12 @@ export default function PDFViewerPage() {
       inFlightDocIdRef.current = resolved;
       stop(); // Reset TTS when loading new document
       for (let attempt = 0; attempt < 2; attempt += 1) {
-        const result = await setCurrentDocument(resolved);
-        if (result === 'loaded') {
+        const loaded = await setCurrentDocument(resolved);
+        if (loaded) {
           loadSucceeded = true;
           loadedDocIdRef.current = resolved;
           break;
         }
-        if (result === 'superseded') {
-          // A newer load (or unmount) is now authoritative; it owns the loading
-          // lifecycle. Bail without surfacing an error to avoid the spurious
-          // "Failed to load" screen on first launch.
-          return;
-        }
         if (attempt === 0) {
           await new Promise((resolve) => setTimeout(resolve, 250));
         }
@@ -144,11 +145,11 @@ export default function PDFViewerPage() {
       if (startedLoad) {
         inFlightDocIdRef.current = null;
       }
-      if (startedLoad && loadSucceeded) {
+      if (!didRedirect && startedLoad && loadSucceeded) {
         setIsLoading(false);
       }
     }
-  }, [isLoading, id, setCurrentDocument, stop]);
+  }, [isLoading, id, router, setCurrentDocument, stop]);
 
   useEffect(() => {
     loadDocument();

src/app/(app)/pdf/[id]/usePdfDocument.ts

@@ -22,8 +22,10 @@ import {
   ensureParsedPdfDocumentOperation,
   forceReparsePdfDocument,
   getDocumentMetadata,
+  getDocumentSettings,
   getParsedPdfDocument,
   ParsedPdfNotReadyError,
+  putDocumentSettings,
   subscribeParsedPdfDocumentEvents,
 } from '@/lib/client/api/documents';
 import { createPdfAudiobookSourceAdapter } from '@/lib/client/audiobooks/adapters/pdf';
@@ -54,16 +56,6 @@ import type {
 } from '@/types/tts';
 import type { AudiobookGenerationSettings, TTSSegmentLocator } from '@/types/client';
 import { clampSegmentPreloadDepth } from '@/types/config';
-import { useDocumentSettings } from '@/hooks/useDocumentSettings';
-
-/**
- * Outcome of a `setCurrentDocument` call.
- * - `loaded`: the document was fetched and is now the active document.
- * - `superseded`: the load was aborted/replaced by a newer load (or unmount).
- *    A newer load is authoritative; callers must NOT treat this as an error.
- * - `failed`: a genuine failure (not found, wrong type, network error).
- */
-export type SetCurrentDocumentResult = 'loaded' | 'superseded' | 'failed';
 
 /**
  * Interface defining all available methods and properties for the PDF route.
@@ -86,7 +78,7 @@ export interface PdfDocumentState {
   parsedOverlayEnabled: boolean;
   setParsedOverlayEnabled: (enabled: boolean) => void;
   forceReparseParsedPdf: () => Promise<void>;
-  setCurrentDocument: (id: string) => Promise<SetCurrentDocumentResult>;
+  setCurrentDocument: (id: string) => Promise<boolean>;
   clearCurrDoc: () => void;
 
   // PDF functionality
@@ -147,6 +139,8 @@ export function usePdfDocument(): PdfDocumentState {
     registerVisualPageChangeHandler,
   } = useTTS();
   const {
+    apiKey,
+    baseUrl,
     providerRef,
     segmentPreloadDepthPages,
     ttsSegmentMaxBlockLength,
@@ -164,11 +158,6 @@ export function usePdfDocument(): PdfDocumentState {
   const [parseProgress, setParseProgress] = useState<PdfParseProgress | null>(null);
   const [, setActiveParseOpId] = useState<string | null>(null);
   const [documentSettings, setDocumentSettings] = useState<DocumentSettings>(DEFAULT_DOCUMENT_SETTINGS);
-  const serverDocumentSettings = useDocumentSettings(currDocId);
-  useEffect(() => {
-    if (!serverDocumentSettings.query.data?.settings) return;
-    setDocumentSettings(mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, serverDocumentSettings.query.data.settings));
-  }, [serverDocumentSettings.query.data?.settings]);
   useEffect(() => {
     setDocumentLanguage(documentSettings.language ?? 'auto');
     lastPreparedPlaybackPageRef.current = null;
@@ -217,6 +206,17 @@ export function usePdfDocument(): PdfDocumentState {
     pageTextCacheRef.current.clear();
   }, []);
 
+  const fetchDocumentSettings = useCallback(async (documentId: string, signal: AbortSignal): Promise<void> => {
+    try {
+      const response = await getDocumentSettings(documentId, { signal });
+      setDocumentSettings(mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, response.settings));
+    } catch (error) {
+      if (error instanceof DOMException && error.name === 'AbortError') return;
+      console.warn('Failed to load document settings, using defaults:', error);
+      setDocumentSettings(DEFAULT_DOCUMENT_SETTINGS);
+    }
+  }, []);
+
   const startParsedEventStream = useCallback((documentId: string, initialOpId: string) => {
     parseStreamAbortRef.current?.abort();
     parseSseCloseRef.current?.();
@@ -516,12 +516,12 @@ export function usePdfDocument(): PdfDocumentState {
 
   /**
    * Sets the current document based on its ID
-   * Retrieves document from server metadata and the browser blob cache.
+   * Retrieves document from IndexedDB
    * 
    * @param {string} id - The unique identifier of the document to set
    * @returns {Promise<void>}
    */
-  const setCurrentDocument = useCallback(async (id: string): Promise<SetCurrentDocumentResult> => {
+  const setCurrentDocument = useCallback(async (id: string): Promise<boolean> => {
     // --- race-condition guard ---
     const seq = ++docLoadSeqRef.current;
     docLoadAbortRef.current?.abort();
@@ -554,12 +554,13 @@ export function usePdfDocument(): PdfDocumentState {
       setDocumentSettings(DEFAULT_DOCUMENT_SETTINGS);
 
       const meta = await getDocumentMetadata(id, { signal: controller.signal });
-      if (seq !== docLoadSeqRef.current) return 'superseded'; // a newer load took over
+      if (seq !== docLoadSeqRef.current) return false; // stale
       if (!meta) {
         console.error('Document not found on server');
-        return 'failed';
+        return false;
       }
       if (meta.type === 'pdf') {
+        void fetchDocumentSettings(id, controller.signal);
         void resolveParsedDocumentState(id, controller.signal).catch((error) => {
           if (controller.signal.aborted) return;
           console.error('Failed to resolve parsed PDF state:', error);
@@ -567,29 +568,28 @@ export function usePdfDocument(): PdfDocumentState {
       }
 
       const doc = await ensureCachedDocument(meta, { signal: controller.signal });
-      if (seq !== docLoadSeqRef.current) return 'superseded'; // a newer load took over
+      if (seq !== docLoadSeqRef.current) return false; // stale
       if (doc.type !== 'pdf') {
         console.error('Document is not a PDF');
-        return 'failed';
+        return false;
       }
 
       setCurrDocName(doc.name);
       // IMPORTANT: keep an immutable copy. pdf.js may transfer/detach the
       // buffer passed into the worker; we always pass clones to react-pdf.
       setCurrDocData(doc.data.slice(0));
-      return 'loaded';
+      return true;
     } catch (error) {
-      // An aborted load means a newer selection (or unmount) took over; not a failure.
-      if (error instanceof DOMException && error.name === 'AbortError') return 'superseded';
-      if (controller.signal.aborted) return 'superseded';
+      if (error instanceof DOMException && error.name === 'AbortError') return false;
       console.error('Failed to get document:', error);
-      return 'failed';
+      return false;
     } finally {
       // Clean up the controller only if it's still ours (a newer call hasn't replaced it).
       if (docLoadAbortRef.current === controller) {
         docLoadAbortRef.current = null;
       }
     }
+    return false;
   }, [
     setCurrDocId,
     setCurrDocName,
@@ -597,6 +597,7 @@ export function usePdfDocument(): PdfDocumentState {
     setCurrDocPages,
     setCurrDocText,
     setPdfDocument,
+    fetchDocumentSettings,
     resolveParsedDocumentState,
   ]);
 
@@ -604,11 +605,12 @@ export function usePdfDocument(): PdfDocumentState {
     if (!currDocId) return;
     setDocumentSettings(settings);
     try {
-      await serverDocumentSettings.mutation.mutateAsync(settings);
+      const updated = await putDocumentSettings(currDocId, settings);
+      setDocumentSettings(mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, updated.settings));
     } catch (error) {
       console.warn('Failed to persist document settings:', error);
     }
-  }, [currDocId, serverDocumentSettings.mutation]);
+  }, [currDocId]);
 
   const forceReparseParsedPdf = useCallback(async (): Promise<void> => {
     if (!currDocId) return;
@@ -682,6 +684,8 @@ export function usePdfDocument(): PdfDocumentState {
     try {
       return await runAudiobookGeneration({
         adapter: audiobookAdapter,
+        apiKey,
+        baseUrl,
         defaultProvider: providerRef,
         onProgress,
         signal,
@@ -694,7 +698,7 @@ export function usePdfDocument(): PdfDocumentState {
       console.error('Error creating audiobook:', error);
       throw error;
     }
-  }, [audiobookAdapter, providerRef]);
+  }, [audiobookAdapter, apiKey, baseUrl, providerRef]);
 
   /**
    * Regenerates a specific chapter (page) of the PDF audiobook
@@ -713,6 +717,8 @@ export function usePdfDocument(): PdfDocumentState {
         bookId,
         format,
         signal,
+        apiKey,
+        baseUrl,
         defaultProvider: providerRef,
         settings,
       });
@@ -723,7 +729,7 @@ export function usePdfDocument(): PdfDocumentState {
       console.error('Error regenerating page:', error);
       throw error;
     }
-  }, [audiobookAdapter, providerRef]);
+  }, [audiobookAdapter, apiKey, baseUrl, providerRef]);
 
   /**
    * Effect hook to initialize TTS as non-EPUB mode

src/app/api/audiobook/chapter/route.ts

@@ -477,7 +477,10 @@ export async function POST(request: NextRequest) {
     providerForError = requestedProvider;
     const credResolved = await resolveTtsCredentials({
       providerHeader: requestedProvider,
+      apiKeyHeader: request.headers.get('x-openai-key'),
+      baseUrlHeader: request.headers.get('x-openai-base-url'),
       fallbackProvider: runtimeConfig.defaultTtsProvider,
+      restrictUserApiKeys: runtimeConfig.restrictUserApiKeys,
     });
     if ('error' in credResolved) {
       if (credResolved.error === 'no_shared_provider_configured') {

src/app/api/documents/[id]/opened/route.ts

@@ -1,27 +0,0 @@
-import { and, eq } from 'drizzle-orm';
-import { NextRequest, NextResponse } from 'next/server';
-import { db } from '@openreader/database';
-import { documents } from '@openreader/database/schema';
-import { resolveUserStateScope } from '@/lib/server/user/resolve-state-scope';
-import { nowTimestampMs } from '@/lib/shared/timestamps';
-import { errorResponse } from '@/lib/server/errors/next-response';
-
-export async function PUT(req: NextRequest, ctx: { params: Promise<{ id: string }> }) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const { id } = await ctx.params;
-    const recentlyOpenedAt = nowTimestampMs();
-    const rows = await db.update(documents).set({ recentlyOpenedAt }).where(and(
-      eq(documents.userId, scope.ownerUserId),
-      eq(documents.id, id.toLowerCase()),
-    )).returning({ id: documents.id });
-    if (!rows[0]) return NextResponse.json({ error: 'Not found' }, { status: 404 });
-    return NextResponse.json({ documentId: rows[0].id, recentlyOpenedAt });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to update recently opened state',
-      normalize: { code: 'DOCUMENT_OPENED_UPDATE_FAILED', errorClass: 'db' },
-    });
-  }
-}

src/app/api/documents/blob/preview/ensure/route.ts

@@ -45,7 +45,6 @@ export async function GET(req: NextRequest) {
         status: 'ready',
         presignUrl,
         fallbackUrl,
-        previewVersion: preview.eTag || String(doc.lastModified),
         ...(directUrl ? { directUrl } : {}),
       },
       {

src/app/api/documents/folders/route.ts

@@ -1,43 +0,0 @@
-import { and, eq, inArray } from 'drizzle-orm';
-import { NextRequest, NextResponse } from 'next/server';
-import { db } from '@openreader/database';
-import { documents, userFolders } from '@openreader/database/schema';
-import { resolveUserStateScope } from '@/lib/server/user/resolve-state-scope';
-import { errorResponse } from '@/lib/server/errors/next-response';
-
-export async function PATCH(req: NextRequest) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const body = (await req.json().catch(() => null)) as { documentIds?: unknown; folderId?: unknown } | null;
-    const documentIds = Array.isArray(body?.documentIds)
-      ? Array.from(new Set(body.documentIds.filter((id): id is string => typeof id === 'string')))
-      : [];
-    const folderId = body?.folderId === null ? null : typeof body?.folderId === 'string' ? body.folderId : undefined;
-    if (documentIds.length === 0 || folderId === undefined) {
-      return NextResponse.json({ error: 'documentIds and folderId are required' }, { status: 400 });
-    }
-    const owned = await db.select({ id: documents.id }).from(documents).where(and(
-      eq(documents.userId, scope.ownerUserId),
-      inArray(documents.id, documentIds),
-    ));
-    if (owned.length !== documentIds.length) return NextResponse.json({ error: 'One or more documents were not found' }, { status: 404 });
-    if (folderId) {
-      const folder = await db.select({ id: userFolders.id }).from(userFolders).where(and(
-        eq(userFolders.userId, scope.ownerUserId),
-        eq(userFolders.id, folderId),
-      )).limit(1);
-      if (!folder[0]) return NextResponse.json({ error: 'Folder not found' }, { status: 404 });
-    }
-    await db.update(documents).set({ folderId }).where(and(
-      eq(documents.userId, scope.ownerUserId),
-      inArray(documents.id, documentIds),
-    ));
-    return NextResponse.json({ success: true, documentIds, folderId });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to move documents',
-      normalize: { code: 'DOCUMENT_FOLDER_UPDATE_FAILED', errorClass: 'db' },
-    });
-  }
-}

src/app/api/documents/route.ts

@@ -64,8 +64,6 @@ export async function GET(req: NextRequest) {
       size: number;
       lastModified: number;
       filePath: string;
-      folderId: string | null;
-      recentlyOpenedAt: number | null;
     }>;
 
     const results: BaseDocument[] = rows.map((doc) => {
@@ -77,9 +75,6 @@ export async function GET(req: NextRequest) {
         lastModified: Number(doc.lastModified),
         type,
         scope: 'user',
-        folderId: doc.folderId ?? undefined,
-        recentlyOpenedAt: doc.recentlyOpenedAt == null ? undefined : Number(doc.recentlyOpenedAt),
-        contentVersion: doc.id,
       };
     });
 

src/app/api/folders/[id]/route.ts

@@ -1,52 +0,0 @@
-import { and, eq } from 'drizzle-orm';
-import { NextRequest, NextResponse } from 'next/server';
-import { db } from '@openreader/database';
-import { documents, userFolders } from '@openreader/database/schema';
-import { resolveUserStateScope } from '@/lib/server/user/resolve-state-scope';
-import { nowTimestampMs } from '@/lib/shared/timestamps';
-import { errorResponse } from '@/lib/server/errors/next-response';
-
-export const dynamic = 'force-dynamic';
-
-export async function PUT(req: NextRequest, ctx: { params: Promise<{ id: string }> }) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const { id } = await ctx.params;
-    const body = (await req.json().catch(() => null)) as { name?: unknown; position?: unknown } | null;
-    const name = typeof body?.name === 'string' ? body.name.trim().slice(0, 200) : undefined;
-    const position = Number.isFinite(body?.position) ? Number(body?.position) : undefined;
-    if (!name && position === undefined) return NextResponse.json({ error: 'No valid fields provided' }, { status: 400 });
-    const rows = await db.update(userFolders).set({
-      ...(name ? { name } : {}),
-      ...(position !== undefined ? { position } : {}),
-      updatedAt: nowTimestampMs(),
-    }).where(and(eq(userFolders.id, id), eq(userFolders.userId, scope.ownerUserId))).returning();
-    if (!rows[0]) return NextResponse.json({ error: 'Not found' }, { status: 404 });
-    return NextResponse.json({ folder: rows[0] });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to update folder',
-      normalize: { code: 'FOLDER_UPDATE_FAILED', errorClass: 'db' },
-    });
-  }
-}
-
-export async function DELETE(req: NextRequest, ctx: { params: Promise<{ id: string }> }) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const { id } = await ctx.params;
-    await db.update(documents).set({ folderId: null }).where(and(
-      eq(documents.userId, scope.ownerUserId),
-      eq(documents.folderId, id),
-    ));
-    await db.delete(userFolders).where(and(eq(userFolders.id, id), eq(userFolders.userId, scope.ownerUserId)));
-    return NextResponse.json({ success: true });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to delete folder',
-      normalize: { code: 'FOLDER_DELETE_FAILED', errorClass: 'db' },
-    });
-  }
-}

src/app/api/folders/route.ts

@@ -1,81 +0,0 @@
-import { and, asc, eq, inArray } from 'drizzle-orm';
-import { NextRequest, NextResponse } from 'next/server';
-import { db } from '@openreader/database';
-import { documents, userFolders } from '@openreader/database/schema';
-import { resolveUserStateScope } from '@/lib/server/user/resolve-state-scope';
-import { nowTimestampMs } from '@/lib/shared/timestamps';
-import { errorResponse } from '@/lib/server/errors/next-response';
-
-export const dynamic = 'force-dynamic';
-
-export async function GET(req: NextRequest) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const rows = await db.select().from(userFolders)
-      .where(eq(userFolders.userId, scope.ownerUserId))
-      .orderBy(asc(userFolders.position), asc(userFolders.createdAt));
-    return NextResponse.json({ folders: rows });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to load folders',
-      normalize: { code: 'FOLDERS_LOAD_FAILED', errorClass: 'db' },
-    });
-  }
-}
-
-export async function POST(req: NextRequest) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const body = (await req.json().catch(() => null)) as { id?: unknown; name?: unknown; documentIds?: unknown } | null;
-    const name = typeof body?.name === 'string' ? body.name.trim().slice(0, 200) : '';
-    if (!name) return NextResponse.json({ error: 'Folder name is required' }, { status: 400 });
-    const documentIds = Array.isArray(body?.documentIds)
-      ? Array.from(new Set(body.documentIds.filter((id): id is string => typeof id === 'string')))
-      : [];
-    if (documentIds.length > 0) {
-      const owned = await db.select({ id: documents.id }).from(documents).where(and(
-        eq(documents.userId, scope.ownerUserId),
-        inArray(documents.id, documentIds),
-      ));
-      if (owned.length !== documentIds.length) {
-        return NextResponse.json({ error: 'One or more documents were not found' }, { status: 404 });
-      }
-    }
-    const id = typeof body?.id === 'string' && /^[a-zA-Z0-9-]{1,100}$/.test(body.id)
-      ? body.id
-      : crypto.randomUUID();
-    const now = nowTimestampMs();
-    await db.transaction(async (tx: typeof db) => {
-      await tx.insert(userFolders).values({ id, userId: scope.ownerUserId, name, position: now, createdAt: now, updatedAt: now });
-      if (documentIds.length > 0) {
-        await tx.update(documents).set({ folderId: id }).where(and(
-          eq(documents.userId, scope.ownerUserId),
-          inArray(documents.id, documentIds),
-        ));
-      }
-    });
-    return NextResponse.json({ folder: { id, userId: scope.ownerUserId, name, position: now, createdAt: now, updatedAt: now } });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to create folder',
-      normalize: { code: 'FOLDER_CREATE_FAILED', errorClass: 'db' },
-    });
-  }
-}
-
-export async function DELETE(req: NextRequest) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    await db.update(documents).set({ folderId: null }).where(eq(documents.userId, scope.ownerUserId));
-    await db.delete(userFolders).where(eq(userFolders.userId, scope.ownerUserId));
-    return NextResponse.json({ success: true });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to delete folders',
-      normalize: { code: 'FOLDERS_DELETE_FAILED', errorClass: 'db' },
-    });
-  }
-}

src/app/api/tts/segments/ensure/route.ts

@@ -183,7 +183,10 @@ export async function POST(request: NextRequest) {
     });
     const requestCreds = await resolveTtsCredentials({
       providerHeader: parsed.settings.providerRef,
+      apiKeyHeader: request.headers.get('x-openai-key'),
+      baseUrlHeader: request.headers.get('x-openai-base-url'),
       fallbackProvider: runtimeConfig.defaultTtsProvider,
+      restrictUserApiKeys: runtimeConfig.restrictUserApiKeys,
     });
     if ('error' in requestCreds) {
       const status = requestCreds.error === 'no_shared_provider_configured' ? 503 : 404;

src/app/api/tts/voices/route.ts

@@ -20,7 +20,10 @@ export async function GET(req: NextRequest) {
     const runtimeConfig = await getResolvedRuntimeConfig();
     const resolved = await resolveTtsCredentials({
       providerHeader: req.headers.get('x-tts-provider'),
+      apiKeyHeader: req.headers.get('x-openai-key'),
+      baseUrlHeader: req.headers.get('x-openai-base-url'),
       fallbackProvider: runtimeConfig.defaultTtsProvider,
+      restrictUserApiKeys: runtimeConfig.restrictUserApiKeys,
     });
 
     if ('error' in resolved) {

src/app/api/user/claim/route.ts

@@ -2,7 +2,7 @@ import { NextRequest, NextResponse } from 'next/server';
 import { claimAnonymousData } from '@/lib/server/user/claim-data';
 import { auth } from '@/lib/server/auth/auth';
 import { db } from '@openreader/database';
-import { audiobooks, documentSettings, documents, userDocumentProgress, userFolders, userOnboarding, userPreferences } from '@openreader/database/schema';
+import { audiobooks, documentSettings, documents, userDocumentProgress, userPreferences } from '@openreader/database/schema';
 import { count, eq, ne } from 'drizzle-orm';
 import { getOpenReaderTestNamespace, getUnclaimedUserIdForNamespace } from '@/lib/server/testing/test-namespace';
 import { errorToLog, serverLogger } from '@/lib/server/logger';
@@ -26,16 +26,14 @@ async function checkClaimMigrationReadiness(): Promise<NextResponse | null> {
 
 async function getClaimableCounts(
   unclaimedUserId: string,
-): Promise<{ documents: number; audiobooks: number; preferences: number; progress: number; documentSettings: number; folders: number; onboarding: number }> {
-  const [[docCount], [bookCount], [preferencesCount], [progressCount], [settingsCount], [folderCount], [onboardingCount]] =
+): Promise<{ documents: number; audiobooks: number; preferences: number; progress: number; documentSettings: number }> {
+  const [[docCount], [bookCount], [preferencesCount], [progressCount], [settingsCount]] =
     await Promise.all([
       db.select({ count: count() }).from(documents).where(eq(documents.userId, unclaimedUserId)),
       db.select({ count: count() }).from(audiobooks).where(eq(audiobooks.userId, unclaimedUserId)),
       db.select({ count: count() }).from(userPreferences).where(eq(userPreferences.userId, unclaimedUserId)),
       db.select({ count: count() }).from(userDocumentProgress).where(eq(userDocumentProgress.userId, unclaimedUserId)),
       db.select({ count: count() }).from(documentSettings).where(eq(documentSettings.userId, unclaimedUserId)),
-      db.select({ count: count() }).from(userFolders).where(eq(userFolders.userId, unclaimedUserId)),
-      db.select({ count: count() }).from(userOnboarding).where(eq(userOnboarding.userId, unclaimedUserId)),
     ]);
 
   return {
@@ -44,8 +42,6 @@ async function getClaimableCounts(
     preferences: Number(preferencesCount?.count ?? 0),
     progress: Number(progressCount?.count ?? 0),
     documentSettings: Number(settingsCount?.count ?? 0),
-    folders: Number(folderCount?.count ?? 0),
-    onboarding: Number(onboardingCount?.count ?? 0),
   };
 }
 

src/app/api/user/export/route.ts

@@ -12,8 +12,6 @@ import {
   userDocumentProgress,
   userJobEvents,
   userPreferences,
-  userFolders,
-  userOnboarding,
   userTtsChars,
 } from '@openreader/database/schema';
 import * as authSchemaSqlite from '@openreader/database/schema-auth-sqlite';
@@ -67,8 +65,6 @@ export async function GET(req: NextRequest) {
     segmentVariants,
     userDocs,
     userAudiobooks,
-    folders,
-    onboarding,
   ] = await Promise.all([
     db.select().from(userPreferences).where(eq(userPreferences.userId, userId)).limit(1),
     db
@@ -111,8 +107,6 @@ export async function GET(req: NextRequest) {
       .from(audiobooks)
       .where(eq(audiobooks.userId, userId))
       .orderBy(desc(audiobooks.createdAt)),
-    db.select().from(userFolders).where(eq(userFolders.userId, userId)).orderBy(userFolders.position),
-    db.select().from(userOnboarding).where(eq(userOnboarding.userId, userId)).limit(1),
   ]);
 
   const authSchema = process.env.POSTGRES_URL ? authSchemaPostgres : authSchemaSqlite;
@@ -196,8 +190,6 @@ export async function GET(req: NextRequest) {
         exportedAtMs,
         profileData,
         preferences: prefs[0] ?? null,
-        folders,
-        onboarding: onboarding[0] ?? null,
         readingHistory: progress,
         ttsUsage,
         jobEvents,

src/app/api/user/state/changelog/version-check/route.ts

@@ -1,15 +1,26 @@
 import { eq } from 'drizzle-orm';
 import { NextRequest, NextResponse } from 'next/server';
 import { db } from '@openreader/database';
-import { userOnboarding } from '@openreader/database/schema';
+import { userPreferences } from '@openreader/database/schema';
 import { normalizeVersion, shouldOpenChangelogForVersionChange } from '@/lib/shared/changelog';
 import { nowTimestampMs } from '@/lib/shared/timestamps';
 import { resolveUserStateScope } from '@/lib/server/user/resolve-state-scope';
 import { errorToLog, serverLogger } from '@/lib/server/logger';
 import { errorResponse } from '@/lib/server/errors/next-response';
+import {
+  deserializeUserPreferencesPayload,
+  extractUserPreferencesMeta,
+  withUserPreferencesMeta,
+  USER_PREFERENCES_LAST_SEEN_APP_VERSION_KEY,
+} from '@/lib/server/user/preferences-payload';
 
 export const dynamic = 'force-dynamic';
 
+function serializePreferencesForDb(payload: Record<string, unknown>): Record<string, unknown> | string {
+  if (process.env.POSTGRES_URL) return payload;
+  return JSON.stringify(payload);
+}
+
 export async function POST(req: NextRequest) {
   try {
     const scope = await resolveUserStateScope(req);
@@ -27,28 +38,40 @@ export async function POST(req: NextRequest) {
 
     const rows = await db
       .select({
-        lastSeenAppVersion: userOnboarding.lastSeenAppVersion,
+        dataJson: userPreferences.dataJson,
+        clientUpdatedAtMs: userPreferences.clientUpdatedAtMs,
       })
-      .from(userOnboarding)
-      .where(eq(userOnboarding.userId, scope.ownerUserId))
+      .from(userPreferences)
+      .where(eq(userPreferences.userId, scope.ownerUserId))
       .limit(1);
 
     const row = rows[0];
-    const lastSeenVersion = row?.lastSeenAppVersion ?? null;
+    const existingPayload = deserializeUserPreferencesPayload(row?.dataJson);
+    const existingMeta = extractUserPreferencesMeta(existingPayload);
+    const lastSeenVersion = typeof existingMeta.lastSeenAppVersion === 'string'
+      ? existingMeta.lastSeenAppVersion
+      : null;
     const shouldOpen = shouldOpenChangelogForVersionChange(lastSeenVersion, currentVersion);
+    const nextMeta = {
+      ...existingMeta,
+      [USER_PREFERENCES_LAST_SEEN_APP_VERSION_KEY]: currentVersion,
+    };
+    const dataJson = serializePreferencesForDb(withUserPreferencesMeta(existingPayload, nextMeta));
     const updatedAt = nowTimestampMs();
+    const clientUpdatedAtMs = Number(row?.clientUpdatedAtMs ?? 0);
 
     await db
-      .insert(userOnboarding)
+      .insert(userPreferences)
       .values({
         userId: scope.ownerUserId,
-        lastSeenAppVersion: currentVersion,
+        dataJson,
+        clientUpdatedAtMs: clientUpdatedAtMs > 0 ? clientUpdatedAtMs : updatedAt,
         updatedAt,
       })
       .onConflictDoUpdate({
-        target: [userOnboarding.userId],
+        target: [userPreferences.userId],
         set: {
-          lastSeenAppVersion: currentVersion,
+          dataJson,
           updatedAt,
         },
       });

src/app/api/user/state/onboarding/route.ts

@@ -1,78 +0,0 @@
-import { eq } from 'drizzle-orm';
-import { NextRequest, NextResponse } from 'next/server';
-import { db } from '@openreader/database';
-import { userOnboarding } from '@openreader/database/schema';
-import { resolveUserStateScope } from '@/lib/server/user/resolve-state-scope';
-import { nowTimestampMs } from '@/lib/shared/timestamps';
-import { errorResponse } from '@/lib/server/errors/next-response';
-
-export const dynamic = 'force-dynamic';
-
-export async function GET(req: NextRequest) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const rows = await db.select().from(userOnboarding)
-      .where(eq(userOnboarding.userId, scope.ownerUserId)).limit(1);
-    const row = rows[0];
-    return NextResponse.json({
-      onboarding: {
-        privacyAcceptedAtMs: row?.privacyAcceptedAtMs == null ? null : Number(row.privacyAcceptedAtMs),
-        lastSeenAppVersion: row?.lastSeenAppVersion ?? null,
-      },
-    });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to load onboarding state',
-      normalize: { code: 'USER_ONBOARDING_LOAD_FAILED', errorClass: 'db' },
-    });
-  }
-}
-
-export async function PATCH(req: NextRequest) {
-  try {
-    const scope = await resolveUserStateScope(req);
-    if (scope instanceof Response) return scope;
-    const body = (await req.json().catch(() => null)) as {
-      privacyAccepted?: unknown;
-      lastSeenAppVersion?: unknown;
-    } | null;
-    const now = nowTimestampMs();
-    const privacyAcceptedAtMs = body?.privacyAccepted === true
-      ? now
-      : body?.privacyAccepted === false ? null : undefined;
-    const lastSeenAppVersion = typeof body?.lastSeenAppVersion === 'string'
-      ? body.lastSeenAppVersion.trim() || null
-      : undefined;
-    if (privacyAcceptedAtMs === undefined && lastSeenAppVersion === undefined) {
-      return NextResponse.json({ error: 'No valid onboarding fields provided' }, { status: 400 });
-    }
-    await db.insert(userOnboarding).values({
-      userId: scope.ownerUserId,
-      privacyAcceptedAtMs: privacyAcceptedAtMs ?? null,
-      lastSeenAppVersion: lastSeenAppVersion ?? null,
-      updatedAt: now,
-    }).onConflictDoUpdate({
-      target: [userOnboarding.userId],
-      set: {
-        ...(privacyAcceptedAtMs !== undefined ? { privacyAcceptedAtMs } : {}),
-        ...(lastSeenAppVersion !== undefined ? { lastSeenAppVersion } : {}),
-        updatedAt: now,
-      },
-    });
-    const rows = await db.select().from(userOnboarding)
-      .where(eq(userOnboarding.userId, scope.ownerUserId)).limit(1);
-    const row = rows[0];
-    return NextResponse.json({
-      onboarding: {
-        privacyAcceptedAtMs: row?.privacyAcceptedAtMs == null ? null : Number(row.privacyAcceptedAtMs),
-        lastSeenAppVersion: row?.lastSeenAppVersion ?? null,
-      },
-    });
-  } catch (error) {
-    return errorResponse(error, {
-      apiErrorMessage: 'Failed to update onboarding state',
-      normalize: { code: 'USER_ONBOARDING_UPDATE_FAILED', errorClass: 'db' },
-    });
-  }
-}

src/app/api/user/state/preferences/route.ts

@@ -13,6 +13,12 @@ import {
   sanitizePreferencesPatch,
   type PreferenceNormalizationContext,
 } from '@/lib/server/user/preferences-normalize';
+import {
+  deserializeUserPreferencesPayload,
+  extractUserPreferencesMeta,
+  withUserPreferencesMeta,
+  type UserPreferencesMeta,
+} from '@/lib/server/user/preferences-payload';
 
 export const dynamic = 'force-dynamic';
 
@@ -21,22 +27,6 @@ function serializePreferencesForDb(payload: Record<string, unknown>): Record<str
   return JSON.stringify(payload);
 }
 
-function deserializePreferences(value: unknown): Record<string, unknown> {
-  if (typeof value === 'string') {
-    try {
-      const parsed = JSON.parse(value);
-      return parsed && typeof parsed === 'object' && !Array.isArray(parsed)
-        ? parsed as Record<string, unknown>
-        : {};
-    } catch {
-      return {};
-    }
-  }
-  return value && typeof value === 'object' && !Array.isArray(value)
-    ? value as Record<string, unknown>
-    : {};
-}
-
 async function loadPreferenceNormalizationContext(): Promise<PreferenceNormalizationContext> {
   const [runtimeConfig, providers] = await Promise.all([
     getResolvedRuntimeConfig(),
@@ -59,10 +49,11 @@ async function loadPreferenceNormalizationContext(): Promise<PreferenceNormaliza
 function parseStoredPreferences(
   value: unknown,
   context: PreferenceNormalizationContext,
-): { patch: SyncedPreferencesPatch; migrated: boolean } {
-  const payload = deserializePreferences(value);
+): { patch: SyncedPreferencesPatch; migrated: boolean; meta: UserPreferencesMeta } {
+  const payload = deserializeUserPreferencesPayload(value);
+  const meta = extractUserPreferencesMeta(payload);
   const sanitized = sanitizePreferencesPatch(payload, context, { fillMissingProvider: true });
-  return { ...sanitized, migrated: sanitized.migrated || '_meta' in payload };
+  return { ...sanitized, meta };
 }
 
 function normalizeClientUpdatedAtMs(value: unknown): number {
@@ -89,6 +80,7 @@ export async function GET(req: NextRequest) {
     const row = rows[0];
     const stored = parseStoredPreferences(row?.dataJson, normalizationContext);
     const storedPatch = stored.patch;
+    const storedPayload = withUserPreferencesMeta(storedPatch, stored.meta);
     const clientUpdatedAtMs = Number(row?.clientUpdatedAtMs ?? 0);
 
     if (row && stored.migrated) {
@@ -97,14 +89,14 @@ export async function GET(req: NextRequest) {
         .insert(userPreferences)
         .values({
           userId: scope.ownerUserId,
-          dataJson: serializePreferencesForDb(storedPatch),
+          dataJson: serializePreferencesForDb(storedPayload),
           clientUpdatedAtMs: clientUpdatedAtMs > 0 ? clientUpdatedAtMs : updatedAt,
           updatedAt,
         })
         .onConflictDoUpdate({
           target: [userPreferences.userId],
           set: {
-            dataJson: serializePreferencesForDb(storedPatch),
+            dataJson: serializePreferencesForDb(storedPayload),
             updatedAt,
           },
         });
@@ -169,7 +161,8 @@ export async function PUT(req: NextRequest) {
     }
 
     const mergedPatch = { ...existingPatch, ...patch };
-    const dataJson = serializePreferencesForDb(mergedPatch);
+    const payloadWithMeta = withUserPreferencesMeta(mergedPatch, existingStored.meta);
+    const dataJson = serializePreferencesForDb(payloadWithMeta);
     const updatedAt = nowTimestampMs();
 
     await db

src/app/providers.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { ReactNode, useEffect, useState } from 'react';
+import { ReactNode, useState } from 'react';
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
 
 import { ThemeProvider } from '@/contexts/ThemeContext';
@@ -25,15 +25,6 @@ export function Providers({ children, authBaseUrl, allowAnonymousAuthSessions, g
     },
   }));
 
-  useEffect(() => {
-    if (typeof indexedDB === 'undefined') return;
-    try {
-      indexedDB.deleteDatabase('openreader-db');
-    } catch {
-      // Legacy IndexedDB cleanup is best effort and never blocks startup.
-    }
-  }, []);
-
   return (
     <QueryClientProvider client={queryClient}>
       <RuntimeConfigProvider>

src/components/PrivacyModal.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import { useState, useEffect } from 'react';
-import { useOnboardingState } from '@/hooks/useOnboardingState';
+import { updateAppConfig } from '@/lib/client/dexie';
 import { Button, Checkbox, ModalFrame, ModalTitle } from '@/components/ui';
 
 interface PrivacyModalProps {
@@ -47,7 +47,6 @@ function PrivacyModalBody({ origin }: { origin: string }) {
 }
 
 export function PrivacyModal({ isOpen, onAccept, onDismiss }: PrivacyModalProps) {
-  const { mutation } = useOnboardingState();
   const [origin, setOrigin] = useState('');
   const [agreed, setAgreed] = useState(false);
 
@@ -63,7 +62,7 @@ export function PrivacyModal({ isOpen, onAccept, onDismiss }: PrivacyModalProps)
   }, [isOpen]);
 
   const handleAccept = async () => {
-    await mutation.mutateAsync({ privacyAccepted: true });
+    await updateAppConfig({ privacyAccepted: true });
     if (typeof window !== 'undefined') {
       window.dispatchEvent(new Event('openreader:privacyAccepted'));
     }

src/components/SettingsModal.tsx

@@ -22,8 +22,13 @@ import { mimeTypeForDoc, uploadDocuments } from '@/lib/client/api/documents';
 import { cacheStoredDocumentFromBytes, clearDocumentCache } from '@/lib/client/cache/documents';
 import { clearAllDocumentPreviewCaches, clearInMemoryDocumentPreviewCache } from '@/lib/client/cache/previews';
 import { resolveTtsSettingsViewModel } from '@/lib/client/settings/tts-settings';
-import { type TtsProviderType } from '@/lib/shared/tts-provider-catalog';
 import {
+  isBuiltInTtsProviderId,
+  type TtsProviderType,
+} from '@/lib/shared/tts-provider-catalog';
+import {
+  defaultBaseUrlForProviderType,
+  defaultModelForProviderType,
   resolveProviderDefaults,
   resolveEffectiveProviderType,
   resolveTtsProviderModelPolicy,
@@ -33,6 +38,8 @@ import { AdminProvidersPanel } from '@/components/admin/AdminProvidersPanel';
 import { AdminFeaturesPanel } from '@/components/admin/AdminFeaturesPanel';
 import { AdminTasksPanel } from '@/components/admin/AdminTasksPanel';
 import { useSharedProviders } from '@/hooks/useSharedProviders';
+import { flushUserPreferencesSync } from '@/lib/client/api/user-state';
+import toast from 'react-hot-toast';
 import { useLibraryDocumentsQuery } from '@/hooks/useLibraryDocumentsQuery';
 import {
   SidebarDialog,
@@ -212,6 +219,7 @@ export function SettingsModal({
   const runtimeConfig = useRuntimeConfig();
   const showAllProviderModels = runtimeConfig.showAllProviderModels;
   const enableTTSProvidersTab = runtimeConfig.enableTtsProvidersTab;
+  const restrictUserApiKeys = runtimeConfig.restrictUserApiKeys;
   const isOpen = open;
   const setIsOpen = onOpenChange;
   const [isChangelogOpen, setIsChangelogOpen] = useState(false);
@@ -220,8 +228,10 @@ export function SettingsModal({
   const { theme, setTheme, applyCustomColors } = useTheme();
   const [customColors, setCustomColors] = useState<CustomThemeColors>(getCustomThemeColors);
   const [isCustomExpanded, setIsCustomExpanded] = useState(false);
-  const { providerRef, providerType, ttsModel, ttsInstructions, updateConfigKey } = useConfig();
+  const { apiKey, baseUrl, providerRef, providerType, ttsModel, ttsInstructions, updateConfig, updateConfigKey } = useConfig();
   const { refreshDocuments } = useDocuments();
+  const [localApiKey, setLocalApiKey] = useState(apiKey);
+  const [localBaseUrl, setLocalBaseUrl] = useState(baseUrl);
   const [localProviderRef, setLocalProviderRef] = useState(providerRef);
   const [localProviderType, setLocalProviderType] = useState<TtsProviderType>(providerType);
   const [modelValue, setModelValue] = useState(ttsModel);
@@ -269,12 +279,13 @@ export function SettingsModal({
   } = useMemo(() => resolveTtsSettingsViewModel({
     providerRef: localProviderRef,
     providerType: localProviderType,
+    apiKey: localApiKey,
     modelValue,
     customModelInput,
     showAllProviderModels,
     sharedProviders,
-    allowBuiltInProviders: false,
-  }), [localProviderRef, localProviderType, modelValue, customModelInput, showAllProviderModels, sharedProviders]);
+    allowBuiltInProviders: !restrictUserApiKeys,
+  }), [localProviderRef, localProviderType, localApiKey, modelValue, customModelInput, showAllProviderModels, sharedProviders, restrictUserApiKeys]);
   const isSharedSelected = Boolean(selectedSharedProvider);
   const selectedProviderOption = ttsProviders.find((p) => p.id === localProviderRef) ?? ttsProviders[0];
 
@@ -290,11 +301,13 @@ export function SettingsModal({
     // focus refetch in ConfigContext, or async shared-provider loading) must not
     // stomp their in-progress selection. On close, resetToCurrent re-syncs.
     if (isOpen) return;
+    setLocalApiKey(apiKey);
+    setLocalBaseUrl(baseUrl);
     setLocalProviderRef(providerRef);
     setLocalProviderType(providerType);
     setModelValue(ttsModel);
     setLocalTTSInstructions(ttsInstructions);
-  }, [isOpen, providerRef, providerType, ttsModel, ttsInstructions]);
+  }, [isOpen, apiKey, baseUrl, providerRef, providerType, ttsModel, ttsInstructions]);
 
   useEffect(() => {
     if (!ttsModels.some(m => m.id === modelValue) && modelValue !== '') {
@@ -318,9 +331,17 @@ export function SettingsModal({
         setModelValue(shared.defaultModel);
       }
       setLocalTTSInstructions(shared?.defaultInstructions ?? '');
+      setLocalApiKey('');
+      setLocalBaseUrl('');
       setCustomModelInput('');
       return;
     }
+
+    if (isBuiltInTtsProviderId(fallback.providerType)) {
+      setModelValue(defaultModelForProviderType(fallback.providerType));
+      setLocalBaseUrl(defaultBaseUrlForProviderType(fallback.providerType));
+      setCustomModelInput('');
+    }
   }, [selectedProviderOption, ttsProviders, sharedProviders]);
 
   const handleRefresh = async () => {
@@ -438,9 +459,19 @@ export function SettingsModal({
     setShowDeleteAccountConfirm(false);
   };
 
+  const handleInputChange = (type: 'apiKey' | 'baseUrl', value: string) => {
+    if (type === 'apiKey') {
+      setLocalApiKey(value === '' ? '' : value);
+    } else if (type === 'baseUrl') {
+      setLocalBaseUrl(value === '' ? '' : value);
+    }
+  };
+
   const resetToCurrent = useCallback(() => {
     setIsOpen(false);
     setIsChangelogOpen(false);
+    setLocalApiKey(apiKey);
+    setLocalBaseUrl(baseUrl);
     setLocalProviderRef(providerRef);
     setLocalProviderType(providerType);
     setModelValue(ttsModel);
@@ -450,7 +481,7 @@ export function SettingsModal({
     } else {
       setCustomModelInput('');
     }
-  }, [providerRef, providerType, ttsModel, ttsInstructions, ttsModels, setIsOpen]);
+  }, [apiKey, baseUrl, providerRef, providerType, ttsModel, ttsInstructions, ttsModels, setIsOpen]);
 
   const [systemIsDark, setSystemIsDark] = useState(
     typeof window !== 'undefined' && window.matchMedia('(prefers-color-scheme: dark)').matches
@@ -515,6 +546,13 @@ export function SettingsModal({
     model: modelValue,
     sharedProviders,
   });
+  const shouldShowBaseUrl = !restrictUserApiKeys
+    && !isSharedSelected
+    && providerModelPolicy.isResolvedProviderType
+    && providerModelPolicy.providerType !== 'replicate'
+    && providerModelPolicy.providerType !== 'speech-sdk'
+    && (providerModelPolicy.providerType === 'custom-openai' || !localBaseUrl || localBaseUrl === '');
+  const shouldShowApiKey = !restrictUserApiKeys && !isSharedSelected;
   const selectedModel = ttsModels.find(m => m.id === selectedModelId) || ttsModels[0];
   const selectedModelVersion = selectedModel?.id?.includes(':')
     ? selectedModel.id.slice(selectedModel.id.indexOf(':'))
@@ -604,11 +642,53 @@ export function SettingsModal({
                                   setLocalProviderType(defaults.providerType);
                                   setModelValue(defaults.defaultModel);
                                   setLocalTTSInstructions(defaults.defaultInstructions);
+                                  if (provider.shared) {
+                                    // Shared admin provider — credentials live on the server.
+                                    setLocalApiKey('');
+                                    setLocalBaseUrl('');
+                                  } else if (isBuiltInTtsProviderId(provider.providerType)) {
+                                    setLocalBaseUrl(defaultBaseUrlForProviderType(provider.providerType));
+                                  }
                                   setCustomModelInput('');
                                 }}
                               />
                             )}
                           </div>
+                          {restrictUserApiKeys && (
+                            <p className="text-xs text-soft">
+                              This instance restricts user API keys. TTS runs through admin-configured shared providers only.
+                            </p>
+                          )}
+
+                          {shouldShowBaseUrl && (
+                            <div className="space-y-1.5">
+                              <label className={fieldLabelClass}>
+                                API Base URL
+                                {localBaseUrl && <span className="ml-2 text-xs text-accent">(Overriding env)</span>}
+                              </label>
+                              <Input
+                                type="text"
+                                value={localBaseUrl}
+                                onChange={(e) => handleInputChange('baseUrl', e.target.value)}
+                                placeholder="Using environment variable"
+                              />
+                            </div>
+                          )}
+
+                          {shouldShowApiKey && (
+                            <div className="space-y-1.5">
+                              <label className={fieldLabelClass}>
+                                API Key
+                                {localApiKey && <span className="ml-2 text-xs text-accent">(Overriding env)</span>}
+                              </label>
+                              <Input
+                                type="password"
+                                value={localApiKey}
+                                onChange={(e) => handleInputChange('apiKey', e.target.value)}
+                                placeholder="Using environment variable"
+                              />
+                            </div>
+                          )}
                           {isSharedSelected && (
                             <p className="text-xs text-soft">
                               This is a shared provider configured by an admin. API key and base URL are managed server-side.
@@ -693,6 +773,8 @@ export function SettingsModal({
                                   providerRef: runtimeConfig.defaultTtsProvider,
                                   sharedProviders,
                                 });
+                                setLocalApiKey('');
+                                setLocalBaseUrl('');
                                 setLocalProviderRef(defaults.providerRef);
                                 setLocalProviderType(defaults.providerType);
                                 setModelValue(defaults.defaultModel);
@@ -714,6 +796,10 @@ export function SettingsModal({
                                   providerType: selectedProviderType,
                                   sharedProviders,
                                 });
+                                await updateConfig({
+                                  apiKey: restrictUserApiKeys ? '' : (localApiKey || ''),
+                                  baseUrl: restrictUserApiKeys ? '' : (localBaseUrl || ''),
+                                });
                                 await updateConfigKey('providerRef', selectedProviderRef);
                                 await updateConfigKey('providerType', selectedProviderType);
                                 const finalModel = showAllProviderModels
@@ -721,6 +807,16 @@ export function SettingsModal({
                                   : defaults.defaultModel;
                                 await updateConfigKey('ttsModel', finalModel);
                                 await updateConfigKey('ttsInstructions', localTTSInstructions);
+                                // Push the change to the server immediately rather than waiting on
+                                // the debounce, so a quick reload can't lose the save. Surface
+                                // failures instead of silently dropping them.
+                                try {
+                                  await flushUserPreferencesSync();
+                                } catch (error) {
+                                  console.error('Failed to save TTS provider settings:', error);
+                                  toast.error('Failed to save provider settings. Please try again.');
+                                  return;
+                                }
                                 setIsOpen(false);
                               }}
                             >

src/components/auth/ClaimDataModal.tsx

@@ -11,8 +11,6 @@ export type ClaimableCounts = {
   preferences: number;
   progress: number;
   documentSettings: number;
-  folders: number;
-  onboarding: number;
 };
 
 function toClaimableCounts(value: unknown): ClaimableCounts {
@@ -23,8 +21,6 @@ function toClaimableCounts(value: unknown): ClaimableCounts {
     preferences: Number(rec.preferences ?? 0),
     progress: Number(rec.progress ?? 0),
     documentSettings: Number(rec.documentSettings ?? 0),
-    folders: Number(rec.folders ?? 0),
-    onboarding: Number(rec.onboarding ?? 0),
   };
 }
 
@@ -90,8 +86,6 @@ export default function ClaimDataModal({
           <li>{claimableCounts.preferences} preference set(s)</li>
           <li>{claimableCounts.progress} reading progress record(s)</li>
           <li>{claimableCounts.documentSettings} document setting(s)</li>
-          <li>{claimableCounts.folders} folder(s)</li>
-          <li>{claimableCounts.onboarding} onboarding state record(s)</li>
         </ul>
       </div>
 

src/components/doclist/DocumentList.tsx

@@ -1,6 +1,7 @@
 'use client';
 
-import { useCallback, useEffect, useMemo, useRef, useState, type ReactNode } from 'react';
+import { useCallback, useEffect, useMemo, useState, type ReactNode } from 'react';
+import { useLiveQuery } from 'dexie-react-hooks';
 import { useDocuments } from '@/contexts/DocumentContext';
 import type {
   DocumentListDocument,
@@ -12,9 +13,11 @@ import type {
   SortDirection,
   ViewMode,
 } from '@/types/documents';
-import { useFolders } from '@/hooks/useFolders';
-import { useUserPreferences } from '@/hooks/useUserPreferences';
-import { useAuthSession } from '@/hooks/useAuthSession';
+import {
+  getDocumentListState,
+  getDocumentRecentlyOpenedMap,
+  saveDocumentListState,
+} from '@/lib/client/dexie';
 import { ConfirmDialog } from '@/components/ConfirmDialog';
 import { CreateFolderDialog } from '@/components/doclist/CreateFolderDialog';
 import { DocumentListSkeleton } from '@/components/doclist/DocumentListSkeleton';
@@ -199,7 +202,7 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
     normalizeViewMode(cachedState?.viewMode ?? DEFAULT_STATE.viewMode),
   );
   const [iconSize, setIconSize] = useState<IconSize>(cachedState?.iconSize ?? DEFAULT_STATE.iconSize);
-  const [folders, setFolders] = useState<Folder[]>([]);
+  const [folders, setFolders] = useState<Folder[]>(cachedState?.folders ?? DEFAULT_STATE.folders);
   const [showHint, setShowHint] = useState(cachedState?.showHint ?? true);
   const [sidebarWidth, setSidebarWidth] = useState(cachedState?.sidebarWidth ?? DEFAULT_STATE.sidebarWidth);
   const [sidebarFilter, setSidebarFilter] = useState<SidebarFilter>(cachedState?.sidebarFilter ?? 'all');
@@ -210,7 +213,6 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
   const [isUploadDialogOpen, setIsUploadDialogOpen] = useState(false);
 
   const [isInitialized, setIsInitialized] = useState(cachedState !== null);
-  const preferenceWriteTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   const [documentToDelete, setDocumentToDelete] = useState<DocumentToDelete | null>(null);
   const [pendingMerge, setPendingMerge] = useState<
@@ -233,20 +235,18 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
     deleteDocument,
     isHTMLLoading,
   } = useDocuments();
-  const { data: session, isPending: isSessionPending } = useAuthSession();
-  const sessionId = session?.user?.id ?? 'no-session';
-  const { query: preferencesQuery, mutation: preferencesMutation } = useUserPreferences(sessionId, !isSessionPending);
-  const persistPreferences = preferencesMutation.mutate;
-  const folderState = useFolders();
 
   // Load saved state.
   useEffect(() => {
-      if (preferencesQuery.isPending) return;
-      const saved = preferencesQuery.data?.preferences.documentListState;
+    let cancelled = false;
+    (async () => {
+      const saved = await getDocumentListState();
+      if (cancelled) return;
       if (saved) {
         cachedDocumentListState = saved;
         setSortBy(saved.sortBy);
         setSortDirection(saved.sortDirection);
+        setFolders(saved.folders ?? []);
         setShowHint(saved.showHint ?? true);
         setViewMode(normalizeViewMode(saved.viewMode));
         setIconSize(saved.iconSize ?? DEFAULT_STATE.iconSize);
@@ -257,6 +257,7 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
         cachedDocumentListState = null;
         setSortBy(DEFAULT_STATE.sortBy);
         setSortDirection(DEFAULT_STATE.sortDirection);
+        setFolders(DEFAULT_STATE.folders);
         setShowHint(DEFAULT_STATE.showHint);
         setViewMode(DEFAULT_STATE.viewMode);
         setIconSize(DEFAULT_STATE.iconSize);
@@ -265,7 +266,11 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
         setSidebarOpen(!DEFAULT_STATE.sidebarCollapsed);
       }
       setIsInitialized(true);
-  }, [preferencesQuery.data?.preferences.documentListState, preferencesQuery.isPending]);
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, []);
 
   // Persist.
   useEffect(() => {
@@ -273,7 +278,7 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
     const state: DocumentListState = {
       sortBy,
       sortDirection,
-      folders: [],
+      folders,
       collapsedFolders: [],
       showHint,
       viewMode,
@@ -283,34 +288,11 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
       sidebarCollapsed: !sidebarOpen,
     };
     cachedDocumentListState = state;
-    const saved = preferencesQuery.data?.preferences.documentListState;
-    if (
-      saved
-      && saved.sortBy === state.sortBy
-      && saved.sortDirection === state.sortDirection
-      && (saved.showHint ?? true) === state.showHint
-      && normalizeViewMode(saved.viewMode) === state.viewMode
-      && (saved.iconSize ?? DEFAULT_STATE.iconSize) === state.iconSize
-      && (saved.sidebarWidth ?? DEFAULT_STATE.sidebarWidth) === state.sidebarWidth
-      && (saved.sidebarFilter ?? 'all') === state.sidebarFilter
-      && (saved.sidebarCollapsed ?? false) === state.sidebarCollapsed
-    ) {
-      return;
-    }
-    if (preferenceWriteTimer.current) clearTimeout(preferenceWriteTimer.current);
-    preferenceWriteTimer.current = setTimeout(() => {
-      persistPreferences({ documentListState: state });
-      preferenceWriteTimer.current = null;
-    }, 250);
-    return () => {
-      if (preferenceWriteTimer.current) {
-        clearTimeout(preferenceWriteTimer.current);
-        preferenceWriteTimer.current = null;
-      }
-    };
+    void saveDocumentListState(state);
   }, [
     sortBy,
     sortDirection,
+    folders,
     showHint,
     viewMode,
     iconSize,
@@ -318,8 +300,6 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
     sidebarFilter,
     sidebarOpen,
     isInitialized,
-    persistPreferences,
-    preferencesQuery.data?.preferences.documentListState,
   ]);
 
   // Mobile drawer should never auto-open from persisted desktop state.
@@ -341,26 +321,28 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
     () => rawDocuments.map((d) => documentIdentityKey(d)).sort().join('|'),
     [rawDocuments],
   );
+  const recentlyOpenedById = useLiveQuery<Record<string, number>, Record<string, number>>(
+    async () => {
+      try {
+        return await getDocumentRecentlyOpenedMap();
+      } catch (err) {
+        console.warn('Failed to load recently opened cache metadata:', err);
+        return {};
+      }
+    },
+    [rawDocumentIdsKey],
+    {},
+  );
+
   const allDocuments: DocumentListDocument[] = useMemo(
     () =>
       rawDocuments.map((doc) => ({
         ...doc,
-        recentlyOpenedAt: doc.recentlyOpenedAt ?? 0,
+        recentlyOpenedAt: recentlyOpenedById[documentIdentityKey(doc)] ?? 0,
       })),
-    [rawDocuments],
+    [rawDocuments, recentlyOpenedById],
   );
 
-  useEffect(() => {
-    const serverFolders = folderState.query.data ?? [];
-    setFolders(serverFolders.map((folder) => ({
-      id: folder.id,
-      name: folder.name,
-      documents: rawDocuments
-        .filter((doc) => doc.folderId === folder.id)
-        .map((doc) => ({ ...doc, folderId: folder.id })),
-    })));
-  }, [folderState.query.data, rawDocumentIdsKey, rawDocuments]);
-
   const allDocumentsById = useMemo(() => {
     const map = new Map<string, DocumentListDocument>();
     for (const doc of allDocuments) map.set(documentIdentityKey(doc), doc);
@@ -491,11 +473,10 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
           return { ...f, documents: [...f.documents, ...newDocs] };
         }),
       );
-      folderState.move.mutate({ documentIds: item.docs.map((doc) => doc.id), folderId });
       setSidebarFilter(`folder:${folderId}`);
       selection.clear();
     },
-    [folderState.move, selection],
+    [selection],
   );
 
   const handleMergeIntoFolder = useCallback(
@@ -510,74 +491,50 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
     [],
   );
 
-  const createFolderFromPending = useCallback(async () => {
+  const createFolderFromPending = useCallback(() => {
     if (!pendingMerge) return;
     const name =
       newFolderName.trim() ||
       generateDefaultFolderName(pendingMerge.sources[0], pendingMerge.target);
-    const documentIds = [...pendingMerge.sources, pendingMerge.target].map((doc) => doc.id);
-    const folderId = crypto.randomUUID();
+    const folderId = `folder-${Date.now()}`;
+    setFolders((prev) => [
+      ...prev,
+      {
+        id: folderId,
+        name,
+        documents: [
+          ...pendingMerge.sources.map((d) => ({ ...d, folderId })),
+          { ...pendingMerge.target, folderId },
+        ],
+      },
+    ]);
     setPendingMerge(null);
     setNewFolderName('');
     setShowHint(false);
     setSidebarFilter(`folder:${folderId}`);
     selection.clear();
-    const { folder } = await folderState.create.mutateAsync({
-      id: folderId,
-      name,
-      documentIds,
-    });
-    setSidebarFilter(`folder:${folder.id}`);
-  }, [folderState.create, pendingMerge, newFolderName, selection]);
-
-  const handleDismissHint = useCallback(() => {
-    setShowHint(false);
-    persistPreferences({
-      documentListState: {
-        sortBy,
-        sortDirection,
-        folders: [],
-        collapsedFolders: [],
-        showHint: false,
-        viewMode,
-        iconSize,
-        sidebarWidth,
-        sidebarFilter,
-        sidebarCollapsed: !sidebarOpen,
-      },
-    });
-  }, [
-    iconSize,
-    persistPreferences,
-    sidebarFilter,
-    sidebarOpen,
-    sidebarWidth,
-    sortBy,
-    sortDirection,
-    viewMode,
-  ]);
+  }, [pendingMerge, newFolderName, selection]);
 
   const createManualFolder = useCallback(() => {
     const name = newFolderName.trim() || `New Folder`;
-    folderState.create.mutate({ name });
+    const folderId = `folder-${Date.now()}`;
+    setFolders((prev) => [...prev, { id: folderId, name, documents: [] }]);
     setNewFolderName('');
     setManualFolderPrompt(false);
-    setSidebarFilter('all');
-  }, [folderState.create, newFolderName]);
+    setSidebarFilter(`folder:${folderId}`);
+  }, [newFolderName]);
 
   const handleDeleteFolder = useCallback((folderId: string) => {
     setFolders((prev) => prev.filter((f) => f.id !== folderId));
-    folderState.remove.mutate(folderId);
     if (sidebarFilter === `folder:${folderId}`) setSidebarFilter('all');
-  }, [folderState.remove, sidebarFilter]);
+  }, [sidebarFilter]);
 
   const handleClearFolders = useCallback(() => {
     setFolders([]);
-    folderState.clear.mutate();
     if (sidebarFilter.startsWith('folder:')) setSidebarFilter('all');
     setClearFoldersPrompt(false);
     selection.clear();
-  }, [folderState.clear, selection, sidebarFilter]);
+  }, [selection, sidebarFilter]);
 
   // Status bar summary.
   const summary = useMemo(() => {
@@ -709,7 +666,7 @@ function DocumentListInner({ brand, appActions }: DocumentListInnerProps) {
               Drag files onto each other to make folders. Drop into the sidebar to move.
             </p>
             <IconButton
-              onClick={handleDismissHint}
+              onClick={() => setShowHint(false)}
               size="xs"
               className="h-6 w-6"
               aria-label="Dismiss hint"

src/components/doclist/DocumentPreview.tsx

@@ -132,7 +132,7 @@ export function DocumentPreview({ doc }: DocumentPreviewProps) {
             if (status.kind === 'ready') {
               const primedUrl = await primeDocumentPreviewCache(
                 doc.id,
-                status.previewVersion || Number(doc.lastModified),
+                Number(doc.lastModified),
                 previewKey,
                 { signal: controller.signal },
               ).catch(() => null);

src/components/documents/DexieMigrationModal.tsx

@@ -0,0 +1,186 @@
+'use client';
+
+import { useCallback, useEffect, useState } from 'react';
+import { getAllEpubDocuments, getAllHtmlDocuments, getAllPdfDocuments, updateAppConfig } from '@/lib/client/dexie';
+import { listDocuments, mimeTypeForDoc, uploadDocuments } from '@/lib/client/api/documents';
+import { useDocuments } from '@/contexts/DocumentContext';
+import type { BaseDocument } from '@/types/documents';
+import { cacheStoredDocumentFromBytes } from '@/lib/client/cache/documents';
+import { Button, ModalFrame, ModalTitle } from '@/components/ui';
+
+type DexieMigrationModalProps = {
+  isOpen: boolean;
+  localCount: number;
+  missingCount: number;
+  onComplete: () => void;
+};
+
+export function DexieMigrationModal({
+  isOpen,
+  localCount,
+  missingCount,
+  onComplete,
+}: DexieMigrationModalProps) {
+  const { refreshDocuments } = useDocuments();
+  const [displayMissingCount, setDisplayMissingCount] = useState(missingCount);
+  const [isUploading, setIsUploading] = useState(false);
+  const [progress, setProgress] = useState(0);
+  const [status, setStatus] = useState<string>('');
+
+  const closeDisabled = isUploading;
+
+  useEffect(() => {
+    setDisplayMissingCount(missingCount);
+  }, [missingCount, isOpen]);
+
+  const loadLocalDexieDocs = useCallback(async (): Promise<{
+    docs: BaseDocument[];
+    pdfById: Map<string, { id: string; name: string; size: number; lastModified: number; data: ArrayBuffer }>;
+    epubById: Map<string, { id: string; name: string; size: number; lastModified: number; data: ArrayBuffer }>;
+    htmlById: Map<string, { id: string; name: string; size: number; lastModified: number; data: string }>;
+  }> => {
+    const [pdfs, epubs, htmls] = await Promise.all([getAllPdfDocuments(), getAllEpubDocuments(), getAllHtmlDocuments()]);
+    const docs: BaseDocument[] = [
+      ...pdfs.map((d) => ({ id: d.id, name: d.name, size: d.size, lastModified: d.lastModified, type: 'pdf' as const })),
+      ...epubs.map((d) => ({ id: d.id, name: d.name, size: d.size, lastModified: d.lastModified, type: 'epub' as const })),
+      ...htmls.map((d) => ({ id: d.id, name: d.name, size: d.size, lastModified: d.lastModified, type: 'html' as const })),
+    ];
+    const pdfById = new Map(pdfs.map((d) => [d.id, d] as const));
+    const epubById = new Map(epubs.map((d) => [d.id, d] as const));
+    const htmlById = new Map(htmls.map((d) => [d.id, d] as const));
+    return { docs, pdfById, epubById, htmlById };
+  }, []);
+
+  const title = 'Upload your local documents?';
+
+  const handleSkip = useCallback(async () => {
+    await updateAppConfig({ documentsMigrationPrompted: true });
+    onComplete();
+  }, [onComplete]);
+
+  const handleUpload = useCallback(async () => {
+    setIsUploading(true);
+    setProgress(0);
+    setStatus('Preparing upload...');
+
+    try {
+      const { docs, pdfById, epubById, htmlById } = await loadLocalDexieDocs();
+
+      const serverDocs = await listDocuments().catch(() => null);
+      const serverIds = serverDocs ? new Set(serverDocs.map((d) => d.id)) : null;
+      const toUpload = serverIds ? docs.filter((d) => !serverIds.has(d.id)) : docs;
+      setDisplayMissingCount(toUpload.length);
+
+      const encoder = new TextEncoder();
+      for (let i = 0; i < toUpload.length; i++) {
+        const doc = toUpload[i];
+        setStatus(`Uploading ${i + 1}/${toUpload.length}: ${doc.name}`);
+        setProgress((i / Math.max(1, toUpload.length)) * 100);
+
+        // Pull raw data from Dexie for this doc
+        if (doc.type === 'pdf') {
+          const full = pdfById.get(doc.id) ?? null;
+          if (!full) continue;
+          const bytes = full.data.slice(0);
+          const file = new File([full.data], full.name, {
+            type: mimeTypeForDoc(doc),
+            lastModified: full.lastModified,
+          });
+          const uploaded = await uploadDocuments([file]);
+          const stored = uploaded[0] ?? null;
+          if (stored) {
+            await cacheStoredDocumentFromBytes(stored, bytes).catch(() => { });
+          }
+        } else if (doc.type === 'epub') {
+          const full = epubById.get(doc.id) ?? null;
+          if (!full) continue;
+          const bytes = full.data.slice(0);
+          const file = new File([full.data], full.name, {
+            type: mimeTypeForDoc(doc),
+            lastModified: full.lastModified,
+          });
+          const uploaded = await uploadDocuments([file]);
+          const stored = uploaded[0] ?? null;
+          if (stored) {
+            await cacheStoredDocumentFromBytes(stored, bytes).catch(() => { });
+          }
+        } else {
+          const full = htmlById.get(doc.id) ?? null;
+          if (!full) continue;
+          const bytes = encoder.encode(full.data).buffer;
+          const file = new File([full.data], full.name, {
+            type: mimeTypeForDoc(doc),
+            lastModified: full.lastModified,
+          });
+          const uploaded = await uploadDocuments([file]);
+          const stored = uploaded[0] ?? null;
+          if (stored) {
+            await cacheStoredDocumentFromBytes(stored, bytes).catch(() => { });
+          }
+        }
+      }
+
+      setProgress(100);
+      setStatus('Refreshing...');
+      await refreshDocuments();
+      await updateAppConfig({ documentsMigrationPrompted: true });
+      onComplete();
+    } catch (err) {
+      console.error('Dexie migration upload failed:', err);
+      setStatus('Upload failed. You can retry or skip.');
+    } finally {
+      setIsUploading(false);
+    }
+  }, [loadLocalDexieDocs, onComplete, refreshDocuments]);
+
+  return (
+    <ModalFrame
+      open={isOpen}
+      onClose={() => {
+        if (!closeDisabled) onComplete();
+      }}
+      panelTestId="migration-modal"
+      className="z-[80]"
+    >
+      <ModalTitle className="mb-4">{title}</ModalTitle>
+      <div className="space-y-2">
+        <p className="text-sm text-soft mb-2">
+          Found {localCount} document{localCount === 1 ? '' : 's'} stored locally from an older version.
+          {displayMissingCount > 0 ? (
+            <> {displayMissingCount} {displayMissingCount === 1 ? 'is' : 'are'} not here yet.</>
+          ) : null}
+          {' '}This app now stores documents on the server and keeps a local cache for speed.
+        </p>
+        {isUploading && (
+          <div className="space-y-1">
+            <p className="text-xs text-soft">{status}</p>
+            <div className="h-2 w-full rounded bg-surface-sunken">
+              <div className="progress-fill h-2 rounded bg-accent" style={{ width: `${Math.max(1, Math.round(progress))}%` }} />
+            </div>
+          </div>
+        )}
+        {!isUploading && status ? <p className="text-xs text-danger">{status}</p> : null}
+      </div>
+
+      <div className="flex justify-end gap-3 mt-6">
+        <Button
+          data-testid="migration-skip-button"
+          variant="outline"
+          size="sm"
+          onClick={handleSkip}
+          disabled={isUploading}
+        >
+          Skip
+        </Button>
+        <Button
+          variant="primary"
+          size="sm"
+          onClick={handleUpload}
+          disabled={isUploading}
+        >
+          {isUploading ? 'Uploading…' : 'Upload'}
+        </Button>
+      </div>
+    </ModalFrame>
+  );
+}

src/contexts/ConfigContext.tsx

@@ -1,18 +1,27 @@
 'use client';
 
-import { createContext, useContext, useMemo, type ReactNode } from 'react';
-import { APP_CONFIG_DEFAULTS, type ViewType, type SavedVoices, type AppConfigValues } from '@/types/config';
+import { createContext, useCallback, useContext, useEffect, useMemo, useRef, useState, ReactNode } from 'react';
+import { useLiveQuery } from 'dexie-react-hooks';
+import { db, initDB, migrateLegacyDexieDocumentIdsToSha, updateAppConfig } from '@/lib/client/dexie';
+import { APP_CONFIG_DEFAULTS, type ViewType, type SavedVoices, type AppConfigValues, type AppConfigRow } from '@/types/config';
+import { isBuiltInTtsProviderId } from '@/lib/shared/tts-provider-catalog';
 import { resolveProviderDefaults } from '@/lib/shared/tts-provider-policy';
+import { scheduleUserPreferencesSync, cancelPendingPreferenceSync, getUserPreferences, putUserPreferences } from '@/lib/client/api/user-state';
+import { SYNCED_PREFERENCE_KEYS, type SyncedPreferenceKey, type SyncedPreferencesPatch } from '@/types/user-state';
 import { useAuthSession } from '@/hooks/useAuthSession';
-import { useRuntimeConfig } from '@/contexts/RuntimeConfigContext';
+import { useFeatureFlag, useRuntimeConfig } from '@/contexts/RuntimeConfigContext';
+import { buildSyncedPreferencePatch } from '@/lib/client/config/preferences';
 import { applyConfigUpdate } from '@/lib/client/config/updates';
 import { useSharedProviders } from '@/hooks/useSharedProviders';
-import { useUserPreferences } from '@/hooks/useUserPreferences';
-import type { SyncedPreferencesPatch } from '@/types/user-state';
-
+import toast from 'react-hot-toast';
 export type { ViewType } from '@/types/config';
 
+/** Configuration values for the application */
+
+/** Interface defining the configuration context shape and functionality */
 interface ConfigContextType {
+  apiKey: string;
+  baseUrl: string;
   viewType: ViewType;
   voiceSpeed: number;
   audioPlayerSpeed: number;
@@ -31,6 +40,7 @@ interface ConfigContextType {
   ttsModel: string;
   ttsInstructions: string;
   savedVoices: SavedVoices;
+  updateConfig: (newConfig: Partial<{ apiKey: string; baseUrl: string; viewType: ViewType }>) => Promise<void>;
   updateConfigKey: <K extends keyof AppConfigValues>(key: K, value: AppConfigValues[K]) => Promise<void>;
   isLoading: boolean;
   isDBReady: boolean;
@@ -44,82 +54,456 @@ interface ConfigContextType {
 
 const ConfigContext = createContext<ConfigContextType | undefined>(undefined);
 
+/**
+ * Provider component for application configuration
+ * Manages global configuration state and persistence
+ * @param {Object} props - Component props
+ * @param {ReactNode} props.children - Child components to be wrapped by the provider
+ */
 export function ConfigProvider({ children }: { children: ReactNode }) {
-  const { data: session, isPending: isSessionPending } = useAuthSession();
-  const sessionId = session?.user?.id ?? 'no-session';
+  const [isLoading, setIsLoading] = useState(true);
+  const [isDBReady, setIsDBReady] = useState(false);
+  const ttsProvidersTabDisabled = !useFeatureFlag('enableTtsProvidersTab');
+  const restrictUserApiKeys = useFeatureFlag('restrictUserApiKeys');
+  const showAllProviderModels = useFeatureFlag('showAllProviderModels');
+  const didRunStartupMigrations = useRef(false);
+  const didAttemptInitialPreferenceSeedForSession = useRef<string | null>(null);
+  const syncedPreferenceKeys = useMemo(() => new Set<string>(SYNCED_PREFERENCE_KEYS), []);
   const { providers: sharedProviders, isLoading: sharedProvidersLoading } = useSharedProviders();
+  const { data: sessionData, isPending: isSessionPending } = useAuthSession();
+  const sessionKey = sessionData?.user?.id ?? 'no-session';
+  // The instance/admin default provider. An empty user providerRef "inherits"
+  // this, resolved (admin slug -> concrete provider) where the value is used.
   const adminDefaultProviderRef = useRuntimeConfig().defaultTtsProvider;
-  const { query, mutation } = useUserPreferences(sessionId, !isSessionPending);
 
-  const config = useMemo<AppConfigValues>(() => ({
-    ...APP_CONFIG_DEFAULTS,
-    ...(query.data?.preferences ?? {}),
-  }), [query.data?.preferences]);
+  const queueSyncedPreferencePatch = useCallback((patch: Partial<AppConfigValues>) => {
+    if (sessionKey === 'no-session') return;
 
-  const effectiveProvider = useMemo(() => resolveProviderDefaults({
-    providerRef: config.providerRef,
-    providerType: config.providerType,
-    sharedProviders,
-    fallbackProviderRef: adminDefaultProviderRef,
-  }), [adminDefaultProviderRef, config.providerRef, config.providerType, sharedProviders]);
+    const syncedPatch: SyncedPreferencesPatch = {};
+    for (const key of SYNCED_PREFERENCE_KEYS) {
+      if (!(key in patch)) continue;
+      const value = patch[key];
+      if (value === undefined) continue;
+      (syncedPatch as Record<SyncedPreferenceKey, unknown>)[key] = value;
+    }
+    if (Object.keys(syncedPatch).length === 0) return;
+    scheduleUserPreferencesSync(syncedPatch, sessionKey);
+  }, [sessionKey]);
 
+  // Cancel pending/in-flight preference syncs whenever the session changes or on unmount.
+  useEffect(() => {
+    return () => {
+      cancelPendingPreferenceSync();
+    };
+  }, [sessionKey]);
+
+  useEffect(() => {
+    const handler = (event: Event) => {
+      const detail = (event as CustomEvent<{ status?: string; ms?: number }>).detail;
+      const status = detail?.status;
+      if (status === 'opened') {
+        toast.dismiss('dexie-blocked');
+        return;
+      }
+      if (status === 'blocked' || status === 'stalled') {
+        const message =
+          'Database upgrade is waiting for another OpenReader tab. Close other OpenReader tabs and reload.';
+        toast.error(message, { id: 'dexie-blocked', duration: Infinity });
+      }
+    };
+
+    window.addEventListener('openreader:dexie', handler as EventListener);
+    return () => {
+      window.removeEventListener('openreader:dexie', handler as EventListener);
+    };
+  }, []);
+
+  useEffect(() => {
+    const initializeDB = async () => {
+      try {
+        setIsLoading(true);
+        await initDB();
+        setIsDBReady(true);
+      } catch (error) {
+        console.error('Error initializing Dexie:', error);
+      } finally {
+        setIsLoading(false);
+      }
+    };
+
+    initializeDB();
+  }, []);
+
+  useEffect(() => {
+    if (!isDBReady) return;
+    if (didRunStartupMigrations.current) return;
+    didRunStartupMigrations.current = true;
+
+    const run = async () => {
+      try {
+        await migrateLegacyDexieDocumentIdsToSha();
+      } catch (error) {
+        console.warn('Startup migrations failed:', error);
+      }
+    };
+
+    void run();
+  }, [isDBReady]);
+
+  const refreshSyncedPreferencesFromServer = useCallback(async (signal?: AbortSignal) => {
+    if (!isDBReady) return;
+    try {
+      const remote = await getUserPreferences({ signal });
+      if (!remote?.hasStoredPreferences) return;
+      if (!remote.preferences || Object.keys(remote.preferences).length === 0) return;
+      await updateAppConfig(remote.preferences as Partial<AppConfigRow>);
+    } catch (error) {
+      if ((error as Error)?.name === 'AbortError') return;
+      console.warn('Failed to load synced preferences:', error);
+    }
+  }, [isDBReady]);
+
+  useEffect(() => {
+    if (!isDBReady || isSessionPending) return;
+    const controller = new AbortController();
+    refreshSyncedPreferencesFromServer(controller.signal).catch((error) => {
+      if ((error as Error)?.name === 'AbortError') return;
+      console.warn('Synced preferences refresh failed:', error);
+    });
+    return () => controller.abort();
+  }, [isDBReady, isSessionPending, sessionKey, refreshSyncedPreferencesFromServer]);
+
+  useEffect(() => {
+    if (!isDBReady) return;
+    let activeController: AbortController | null = null;
+    const onFocus = () => {
+      if (activeController) activeController.abort();
+      activeController = new AbortController();
+      refreshSyncedPreferencesFromServer(activeController.signal).catch((error) => {
+        if ((error as Error)?.name === 'AbortError') return;
+        console.warn('Focus synced preferences refresh failed:', error);
+      });
+    };
+    window.addEventListener('focus', onFocus);
+    return () => {
+      window.removeEventListener('focus', onFocus);
+      if (activeController) activeController.abort();
+    };
+  }, [isDBReady, refreshSyncedPreferencesFromServer]);
+
+  const appConfig = useLiveQuery(
+    async () => {
+      if (!isDBReady) return null;
+      const row = await db['app-config'].get('singleton');
+      return row ?? null;
+    },
+    [isDBReady],
+    null,
+  );
+
+  const config: AppConfigValues | null = useMemo(() => {
+    if (!appConfig) return null;
+    const { id, ...rest } = appConfig;
+    void id;
+    return { ...APP_CONFIG_DEFAULTS, ...rest };
+  }, [appConfig]);
+
+  useEffect(() => {
+    if (ttsProvidersTabDisabled && isDBReady && appConfig && !sharedProvidersLoading) {
+      const resetPatch: Partial<AppConfigRow> = {};
+
+      // When the provider tab is hidden, clear any user-set provider config back to
+      // "inherit the admin default" (empty) rather than baking in a concrete value.
+      if (appConfig.apiKey !== '') resetPatch.apiKey = '';
+      if (appConfig.baseUrl !== '') resetPatch.baseUrl = '';
+      if (appConfig.providerRef !== '') resetPatch.providerRef = '';
+      if (appConfig.providerType !== 'unknown') resetPatch.providerType = 'unknown';
+      if (appConfig.ttsModel !== '') resetPatch.ttsModel = '';
+      if (appConfig.ttsInstructions !== '') resetPatch.ttsInstructions = '';
+      // Keep voice selection state intact so player/Audiobook voice pickers still
+      // work when the TTS providers tab is hidden. This reset is only for provider
+      // configuration fields.
+
+      if (Object.keys(resetPatch).length === 0) return;
+
+      updateAppConfig(resetPatch).catch((error) => {
+        console.warn('Failed to clear hidden TTS provider settings:', error);
+      });
+      queueSyncedPreferencePatch(resetPatch);
+    }
+  }, [ttsProvidersTabDisabled, isDBReady, appConfig, queueSyncedPreferencePatch, sharedProvidersLoading]);
+
+  useEffect(() => {
+    if (restrictUserApiKeys && isDBReady && appConfig && !sharedProvidersLoading) {
+      const resetPatch: Partial<AppConfigRow> = {};
+
+      if (appConfig.apiKey !== '') resetPatch.apiKey = '';
+      if (appConfig.baseUrl !== '') resetPatch.baseUrl = '';
+      // Built-in providers aren't selectable in restricted mode. Clear any stale
+      // built-in selection (including the old 'custom-openai' default that used to
+      // be baked into every config) back to "inherit the admin default" so the
+      // user follows whatever shared provider the admin has configured.
+      if (isBuiltInTtsProviderId(appConfig.providerRef)) {
+        resetPatch.providerRef = '';
+        resetPatch.providerType = 'unknown';
+        resetPatch.ttsModel = '';
+        resetPatch.ttsInstructions = '';
+      }
+
+      if (Object.keys(resetPatch).length === 0) return;
+
+      updateAppConfig(resetPatch).catch((error) => {
+        console.warn('Failed to enforce restricted user API key mode:', error);
+      });
+      queueSyncedPreferencePatch(resetPatch);
+    }
+  }, [restrictUserApiKeys, isDBReady, appConfig, queueSyncedPreferencePatch, sharedProvidersLoading]);
+
+  useEffect(() => {
+    if (showAllProviderModels || !isDBReady || !appConfig || sharedProvidersLoading) return;
+    // Inheriting (empty providerRef): the effective model is resolved at read
+    // time, so there is nothing to persist/enforce here.
+    if (!appConfig.providerRef) return;
+    const providerDefaults = resolveProviderDefaults({
+      providerRef: appConfig.providerRef,
+      providerType: appConfig.providerType,
+      sharedProviders,
+      fallbackProviderRef: adminDefaultProviderRef,
+    });
+    if (!providerDefaults.defaultModel) return;
+    if (appConfig.ttsModel === providerDefaults.defaultModel) return;
+    const patch: Partial<AppConfigRow> = { ttsModel: providerDefaults.defaultModel };
+    updateAppConfig(patch).catch((error) => {
+      console.warn('Failed to enforce provider default model restriction:', error);
+    });
+    queueSyncedPreferencePatch(patch);
+  }, [showAllProviderModels, isDBReady, appConfig, sharedProviders, adminDefaultProviderRef, queueSyncedPreferencePatch, sharedProvidersLoading]);
+
+  useEffect(() => {
+    if (!isDBReady || !appConfig || isSessionPending) return;
+    if (didAttemptInitialPreferenceSeedForSession.current === sessionKey) return;
+    didAttemptInitialPreferenceSeedForSession.current = sessionKey;
+
+    const controller = new AbortController();
+
+    const run = async () => {
+      try {
+        const remote = await getUserPreferences({ signal: controller.signal });
+        if (remote?.hasStoredPreferences) return;
+
+        // Seed only user-customized (non-default) values. This prevents fresh/default
+        // profiles from overwriting existing server values during first-run races.
+        const patch = buildSyncedPreferencePatch(appConfig, { nonDefaultOnly: true });
+        if (Object.keys(patch).length === 0) return;
+
+        await putUserPreferences(patch, { clientUpdatedAtMs: Date.now(), signal: controller.signal });
+      } catch (error) {
+        if ((error as Error)?.name === 'AbortError') return;
+        console.warn('Failed to seed initial synced preferences from local Dexie:', error);
+      }
+    };
+
+    run().catch((error) => {
+      if ((error as Error)?.name === 'AbortError') return;
+      console.warn('Initial synced preferences seed failed:', error);
+    });
+
+    return () => controller.abort();
+  }, [isDBReady, appConfig, isSessionPending, sessionKey]);
+
+  // Destructure for convenience and to match context shape
+  const {
+    apiKey,
+    baseUrl,
+    viewType,
+    voiceSpeed,
+    audioPlayerSpeed,
+    voice,
+    skipBlank,
+    epubTheme,
+    headerMargin,
+    footerMargin,
+    leftMargin,
+    rightMargin,
+    providerRef,
+    providerType: _persistedProviderType,
+    ttsModel,
+    ttsInstructions,
+    savedVoices,
+    segmentPreloadDepthPages,
+    segmentPreloadSentenceLookahead,
+    ttsSegmentMaxBlockLength,
+    pdfHighlightEnabled,
+    pdfWordHighlightEnabled,
+    epubHighlightEnabled,
+    epubWordHighlightEnabled,
+    htmlHighlightEnabled,
+    htmlWordHighlightEnabled,
+  } = config || APP_CONFIG_DEFAULTS;
+  // Resolve the effective provider for consumers. An empty stored providerRef
+  // means "inherit the admin default", which we resolve here so the reader,
+  // voice pickers, and settings UI all see a concrete, usable provider without
+  // mutating the stored ("inherit") value.
+  const effectiveProvider = useMemo(
+    () => resolveProviderDefaults({
+      providerRef,
+      providerType: _persistedProviderType,
+      sharedProviders,
+      fallbackProviderRef: adminDefaultProviderRef,
+    }),
+    [providerRef, _persistedProviderType, sharedProviders, adminDefaultProviderRef],
+  );
   const effectiveProviderRef = effectiveProvider.providerRef;
-  const effectiveTtsModel = config.ttsModel || effectiveProvider.defaultModel;
-  const effectiveTtsInstructions = config.ttsInstructions || effectiveProvider.defaultInstructions;
+  const providerType = effectiveProvider.providerType;
+  const effectiveTtsModel = ttsModel || effectiveProvider.defaultModel;
+  const effectiveTtsInstructions = ttsInstructions || effectiveProvider.defaultInstructions;
 
-  const updatePatch = async (patch: Partial<AppConfigValues>) => {
-    await mutation.mutateAsync(patch as SyncedPreferencesPatch);
+  useEffect(() => {
+    if (!isDBReady || !appConfig || sharedProvidersLoading) return;
+    // Only persist a resolved providerType for an explicitly chosen provider.
+    // While inheriting (empty providerRef) the type stays unset in storage.
+    if (!appConfig.providerRef) return;
+    if (appConfig.providerType === providerType) return;
+    const patch: Partial<AppConfigRow> = { providerType };
+    updateAppConfig(patch).catch((error) => {
+      console.warn('Failed to persist resolved providerType:', error);
+    });
+    queueSyncedPreferencePatch(patch);
+  }, [isDBReady, appConfig, providerType, queueSyncedPreferencePatch, sharedProvidersLoading]);
+  void _persistedProviderType;
+
+  useEffect(() => {
+    if (!isDBReady || !appConfig || sharedProvidersLoading) return;
+    // Inheriting (empty providerRef): the effective model is resolved at read
+    // time; don't write a concrete model into the "inherit" state.
+    if (!appConfig.providerRef) return;
+    const providerDefaults = resolveProviderDefaults({
+      providerRef: appConfig.providerRef,
+      providerType: appConfig.providerType,
+      sharedProviders,
+      fallbackProviderRef: adminDefaultProviderRef,
+    });
+    if (!providerDefaults.defaultModel) return;
+    if (appConfig.ttsModel === providerDefaults.defaultModel) return;
+    // Heal stale fallback model values that were written while the provider UI
+    // was disabled and shared provider context was unavailable.
+    if (appConfig.ttsModel !== APP_CONFIG_DEFAULTS.ttsModel) return;
+
+    const patch: Partial<AppConfigRow> = { ttsModel: providerDefaults.defaultModel };
+    updateAppConfig(patch).catch((error) => {
+      console.warn('Failed to normalize shared-provider default model:', error);
+    });
+    queueSyncedPreferencePatch(patch);
+  }, [isDBReady, appConfig, sharedProviders, queueSyncedPreferencePatch, adminDefaultProviderRef, sharedProvidersLoading]);
+
+  /**
+   * Updates multiple configuration values simultaneously
+   * Only saves API credentials if they are explicitly set
+   */
+  const updateConfig = async (newConfig: Partial<{ apiKey: string; baseUrl: string; viewType: ViewType }>) => {
+    try {
+      setIsLoading(true);
+      const updates: Partial<AppConfigRow> = {};
+      if (newConfig.apiKey !== undefined) {
+        updates.apiKey = newConfig.apiKey;
+      }
+      if (newConfig.baseUrl !== undefined) {
+        updates.baseUrl = newConfig.baseUrl;
+      }
+      if (newConfig.viewType !== undefined) {
+        updates.viewType = newConfig.viewType;
+      }
+      await updateAppConfig(updates);
+      queueSyncedPreferencePatch(updates);
+    } catch (error) {
+      console.error('Error updating config:', error);
+      throw error;
+    } finally {
+      setIsLoading(false);
+    }
   };
 
+  /**
+   * Updates a single configuration value by key
+   * @param {K} key - The configuration key to update
+   * @param {AppConfigValues[K]} value - The new value for the configuration
+   */
   const updateConfigKey = async <K extends keyof AppConfigValues>(key: K, value: AppConfigValues[K]) => {
-    const { syncPatch } = applyConfigUpdate({
-      providerRef: effectiveProviderRef,
-      providerType: effectiveProvider.providerType,
-      ttsModel: effectiveTtsModel,
-      savedVoices: config.savedVoices,
-    }, key, value);
-    await updatePatch(syncPatch);
-  };
+    try {
+      setIsLoading(true);
+      const { storagePatch, syncPatch } = applyConfigUpdate({
+        providerRef: effectiveProviderRef,
+        providerType,
+        ttsModel: effectiveTtsModel,
+        savedVoices,
+      }, key, value);
 
-  const isLoading = isSessionPending || query.isPending || mutation.isPending || sharedProvidersLoading;
+      await updateAppConfig(storagePatch);
+      if (
+        key === 'voice' ||
+        key === 'providerRef' ||
+        key === 'providerType' ||
+        key === 'ttsModel' ||
+        key === 'savedVoices' ||
+        syncedPreferenceKeys.has(String(key))
+      ) {
+        queueSyncedPreferencePatch(syncPatch);
+      }
+    } catch (error) {
+      console.error(`Error updating config key ${String(key)}:`, error);
+      throw error;
+    } finally {
+      setIsLoading(false);
+    }
+  };
 
   return (
     <ConfigContext.Provider value={{
-      viewType: config.viewType,
-      voiceSpeed: config.voiceSpeed,
-      audioPlayerSpeed: config.audioPlayerSpeed,
-      voice: config.voice,
-      skipBlank: config.skipBlank,
-      epubTheme: config.epubTheme,
-      segmentPreloadDepthPages: config.segmentPreloadDepthPages,
-      segmentPreloadSentenceLookahead: config.segmentPreloadSentenceLookahead,
-      ttsSegmentMaxBlockLength: config.ttsSegmentMaxBlockLength,
-      headerMargin: config.headerMargin,
-      footerMargin: config.footerMargin,
-      leftMargin: config.leftMargin,
-      rightMargin: config.rightMargin,
+      apiKey,
+      baseUrl,
+      viewType,
+      voiceSpeed,
+      audioPlayerSpeed,
+      voice,
+      skipBlank,
+      epubTheme,
+      segmentPreloadDepthPages,
+      segmentPreloadSentenceLookahead,
+      ttsSegmentMaxBlockLength,
+      headerMargin,
+      footerMargin,
+      leftMargin,
+      rightMargin,
       providerRef: effectiveProviderRef,
-      providerType: effectiveProvider.providerType,
+      providerType,
       ttsModel: effectiveTtsModel,
       ttsInstructions: effectiveTtsInstructions,
-      savedVoices: config.savedVoices,
+      savedVoices,
+      updateConfig,
       updateConfigKey,
       isLoading,
-      isDBReady: !isSessionPending && !query.isPending,
-      pdfHighlightEnabled: config.pdfHighlightEnabled,
-      pdfWordHighlightEnabled: config.pdfWordHighlightEnabled,
-      epubHighlightEnabled: config.epubHighlightEnabled,
-      epubWordHighlightEnabled: config.epubWordHighlightEnabled,
-      htmlHighlightEnabled: config.htmlHighlightEnabled,
-      htmlWordHighlightEnabled: config.htmlWordHighlightEnabled,
+      isDBReady,
+      pdfHighlightEnabled,
+      pdfWordHighlightEnabled,
+      epubHighlightEnabled,
+      epubWordHighlightEnabled,
+      htmlHighlightEnabled,
+      htmlWordHighlightEnabled,
     }}>
       {children}
     </ConfigContext.Provider>
   );
 }
 
+/**
+ * Custom hook to consume the configuration context
+ * @returns {ConfigContextType} The configuration context value
+ * @throws {Error} When used outside of ConfigProvider
+ */
 export function useConfig() {
   const context = useContext(ConfigContext);
-  if (!context) throw new Error('useConfig must be used within a ConfigProvider');
+  if (context === undefined) {
+    throw new Error('useConfig must be used within a ConfigProvider');
+  }
   return context;
 }

src/contexts/DocumentContext.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import { createContext, useCallback, useContext, useEffect, useMemo, ReactNode } from 'react';
-import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
+import { useQuery, useQueryClient } from '@tanstack/react-query';
 import type { BaseDocument } from '@/types/documents';
 import {
   deleteDocuments as deleteServerDocuments,
@@ -102,31 +102,10 @@ export function DocumentProvider({ children }: { children: ReactNode }) {
     return { pdfDocs, epubDocs, htmlDocs };
   }, [docs]);
 
-  const uploadMutation = useMutation({
-    mutationFn: (files: File[]) => uploadServerDocuments(files),
-    onSuccess: (stored) => {
-      queryClient.setQueryData<SupportedDocument[]>(documentsQueryKey, (previous) =>
-        mergeStoredDocuments(previous, stored),
-      );
-    },
-    onSettled: () => queryClient.invalidateQueries({ queryKey: documentsQueryKey }),
-  });
-  const deleteMutation = useMutation({
-    mutationFn: (id: string) => deleteServerDocuments({ ids: [id] }),
-    onMutate: async (id) => {
-      await queryClient.cancelQueries({ queryKey: documentsQueryKey });
-      const previous = queryClient.getQueryData<SupportedDocument[]>(documentsQueryKey);
-      queryClient.setQueryData<SupportedDocument[]>(documentsQueryKey, (rows = []) => rows.filter((doc) => doc.id !== id));
-      return { previous };
-    },
-    onError: (_error, _id, context) => queryClient.setQueryData(documentsQueryKey, context?.previous),
-    onSettled: () => queryClient.invalidateQueries({ queryKey: documentsQueryKey }),
-  });
-
   const uploadDocuments = useCallback(async (files: File[]): Promise<BaseDocument[]> => {
     if (files.length === 0) return [];
 
-    const stored = await uploadMutation.mutateAsync(files);
+    const stored = await uploadServerDocuments(files);
     await Promise.allSettled(
       stored.map(async (document, index) => {
         const file = files[index];
@@ -155,13 +134,20 @@ export function DocumentProvider({ children }: { children: ReactNode }) {
       }),
     );
 
+    queryClient.setQueryData<SupportedDocument[]>(documentsQueryKey, (previous) =>
+      mergeStoredDocuments(previous, stored),
+    );
+
     return stored;
-  }, [uploadMutation]);
+  }, [documentsQueryKey, queryClient]);
 
   const deleteDocument = useCallback(async (id: string) => {
-    await deleteMutation.mutateAsync(id);
+    await deleteServerDocuments({ ids: [id] });
     await evictCachedDocument(id);
-  }, [deleteMutation]);
+    queryClient.setQueryData<SupportedDocument[]>(documentsQueryKey, (previous = []) =>
+      previous.filter((document) => document.id !== id),
+    );
+  }, [documentsQueryKey, queryClient]);
 
   return (
     <DocumentContext.Provider value={{

src/contexts/OnboardingFlowContext.tsx

@@ -2,15 +2,16 @@
 
 import { createContext, useCallback, useContext, useEffect, useMemo, useRef, useState, type ReactNode } from 'react';
 import ClaimDataModal, { type ClaimableCounts } from '@/components/auth/ClaimDataModal';
+import { DexieMigrationModal } from '@/components/documents/DexieMigrationModal';
 import { PrivacyModal } from '@/components/PrivacyModal';
 import { useAuthSession } from '@/hooks/useAuthSession';
 import { useRuntimeConfig } from '@/contexts/RuntimeConfigContext';
+import { getAllEpubDocuments, getAllHtmlDocuments, getAllPdfDocuments, getAppConfig, setFirstVisit } from '@/lib/client/dexie';
+import { listDocuments } from '@/lib/client/api/documents';
 import { postChangelogVersionCheck } from '@/lib/client/api/user-state';
 import { scheduleChangelogCheck } from '@/lib/client/changelog-check';
 import { createCoalescedAsyncRunner, resolveNextOnboardingStep } from '@/lib/client/onboarding-flow';
-import { useOnboardingState } from '@/hooks/useOnboardingState';
-import { useQuery } from '@tanstack/react-query';
-import { queryKeys } from '@/lib/client/query-keys';
+import { ONBOARDING_STATE_REGISTRY } from '@/lib/shared/onboarding-state';
 
 type OnboardingFlowContextValue = {
   changelogOpenSignal: number;
@@ -18,14 +19,18 @@ type OnboardingFlowContextValue = {
 
 const OnboardingFlowContext = createContext<OnboardingFlowContextValue | null>(null);
 
+type MigrationPromptState = {
+  shouldPrompt: boolean;
+  localCount: number;
+  missingCount: number;
+};
+
 const EMPTY_CLAIM_COUNTS: ClaimableCounts = {
   documents: 0,
   audiobooks: 0,
   preferences: 0,
   progress: 0,
   documentSettings: 0,
-  folders: 0,
-  onboarding: 0,
 };
 
 function toClaimableCounts(value: unknown): ClaimableCounts {
@@ -36,8 +41,6 @@ function toClaimableCounts(value: unknown): ClaimableCounts {
     preferences: Number(rec.preferences ?? 0),
     progress: Number(rec.progress ?? 0),
     documentSettings: Number(rec.documentSettings ?? 0),
-    folders: Number(rec.folders ?? 0),
-    onboarding: Number(rec.onboarding ?? 0),
   };
 }
 
@@ -50,22 +53,71 @@ async function fetchClaimableCounts(): Promise<ClaimableCounts> {
   return toClaimableCounts(data);
 }
 
+async function getMigrationPromptState(privacyGateSatisfied: boolean): Promise<MigrationPromptState> {
+  const cfg = await getAppConfig();
+  if (!privacyGateSatisfied || cfg?.documentsMigrationPrompted) {
+    return { shouldPrompt: false, localCount: 0, missingCount: 0 };
+  }
+
+  const [pdfs, epubs, htmls] = await Promise.all([
+    getAllPdfDocuments(),
+    getAllEpubDocuments(),
+    getAllHtmlDocuments(),
+  ]);
+  const localDocs = [
+    ...pdfs.map((d) => d.id),
+    ...epubs.map((d) => d.id),
+    ...htmls.map((d) => d.id),
+  ];
+  const localCount = localDocs.length;
+  if (localCount === 0) {
+    return { shouldPrompt: false, localCount: 0, missingCount: 0 };
+  }
+
+  const serverDocs = await listDocuments().catch(() => null);
+  if (!serverDocs) {
+    return { shouldPrompt: true, localCount, missingCount: localCount };
+  }
+
+  const serverIds = new Set(serverDocs.map((d) => d.id));
+  const missingCount = localDocs.filter((id) => !serverIds.has(id)).length;
+  return {
+    shouldPrompt: missingCount > 0,
+    localCount,
+    missingCount,
+  };
+}
+
+type LocalOnboardingSnapshot = {
+  privacyAccepted: boolean;
+  firstVisitSettingsOpened: boolean;
+};
+
+async function readLocalOnboardingSnapshot(): Promise<LocalOnboardingSnapshot> {
+  const appConfig = await getAppConfig();
+  const row = appConfig as Record<string, unknown> | null;
+  const privacyKey = ONBOARDING_STATE_REGISTRY.privacyAccepted.localKey;
+  const firstVisitKey = ONBOARDING_STATE_REGISTRY.firstVisitSettingsOpened.localKey;
+
+  return {
+    privacyAccepted: privacyKey ? Boolean(row?.[privacyKey]) : false,
+    firstVisitSettingsOpened: firstVisitKey ? Boolean(row?.[firstVisitKey]) : false,
+  };
+}
+
 export function OnboardingFlowProvider({ children }: { children: ReactNode }) {
   const { data: session, isPending: isSessionPending } = useAuthSession();
   const runtimeConfig = useRuntimeConfig();
   const user = session?.user as { id?: string; isAnonymous?: boolean } | undefined;
   const userId = user?.id ?? null;
   const isAnonymous = Boolean(user?.isAnonymous);
-  const claimCountsQuery = useQuery({
-    queryKey: queryKeys.claimCounts(userId ?? 'no-session'),
-    queryFn: fetchClaimableCounts,
-    enabled: Boolean(userId && !isAnonymous),
-  });
-  const refetchClaimCounts = claimCountsQuery.refetch;
 
-  const { query: onboardingQuery } = useOnboardingState();
-  const [activeBlockingModal, setActiveBlockingModal] = useState<'privacy' | 'claim' | null>(null);
+  const [activeBlockingModal, setActiveBlockingModal] = useState<'privacy' | 'claim' | 'migration' | null>(null);
   const [claimableCounts, setClaimableCounts] = useState<ClaimableCounts>(EMPTY_CLAIM_COUNTS);
+  const [migrationCounts, setMigrationCounts] = useState<{ localCount: number; missingCount: number }>({
+    localCount: 0,
+    missingCount: 0,
+  });
   const [changelogOpenSignal, setChangelogOpenSignal] = useState(0);
 
   const pendingChangelogOpenRef = useRef(false);
@@ -83,17 +135,9 @@ export function OnboardingFlowProvider({ children }: { children: ReactNode }) {
   );
 
   const runOnceFlow = useCallback(async () => {
-    // Wait until the onboarding state has actually loaded before deciding whether
-    // to show the privacy modal. Otherwise the not-yet-loaded query (data === undefined)
-    // reads as "not accepted", the modal flashes on first paint, then closes once the
-    // real state arrives.
-    const onboardingData = onboardingQuery.data;
-    if (onboardingData === undefined) {
-      return;
-    }
-
+    const local = await readLocalOnboardingSnapshot();
     const privacyRequired = true;
-    const privacyAccepted = !privacyRequired || Boolean(onboardingData.privacyAcceptedAtMs);
+    const privacyAccepted = !privacyRequired || local.privacyAccepted;
 
     const isClaimEligible = Boolean(
       userId
@@ -105,25 +149,26 @@ export function OnboardingFlowProvider({ children }: { children: ReactNode }) {
     let claimHasData = false;
 
     if (isClaimEligible) {
-      claimCounts = (await refetchClaimCounts()).data ?? EMPTY_CLAIM_COUNTS;
+      claimCounts = await fetchClaimableCounts();
       const total = claimCounts.documents
         + claimCounts.audiobooks
         + claimCounts.preferences
         + claimCounts.progress
-        + claimCounts.documentSettings
-        + claimCounts.folders
-        + claimCounts.onboarding;
+        + claimCounts.documentSettings;
       claimHasData = total > 0;
       if (!claimHasData && userId) {
         claimDismissedUsersRef.current.add(userId);
       }
     }
 
+    const migrationState = await getMigrationPromptState(privacyAccepted);
+
     const nextStep = resolveNextOnboardingStep({
       privacyRequired,
       privacyAccepted,
       claimEligible: isClaimEligible,
       claimHasData,
+      migrationRequired: migrationState.shouldPrompt,
       changelogPending: pendingChangelogOpenRef.current,
     });
 
@@ -138,13 +183,26 @@ export function OnboardingFlowProvider({ children }: { children: ReactNode }) {
       return;
     }
 
+    if (nextStep === 'migration') {
+      setMigrationCounts({
+        localCount: migrationState.localCount,
+        missingCount: migrationState.missingCount,
+      });
+      setActiveBlockingModal('migration');
+      return;
+    }
+
     setActiveBlockingModal(null);
 
+    if (!local.firstVisitSettingsOpened) {
+      await setFirstVisit(true);
+    }
+
     if (nextStep === 'changelog') {
       pendingChangelogOpenRef.current = false;
       setChangelogOpenSignal((value) => value + 1);
     }
-  }, [isAnonymous, onboardingQuery.data, refetchClaimCounts, userId]);
+  }, [isAnonymous, userId]);
 
   runOnceFlowRef.current = runOnceFlow;
 
@@ -156,6 +214,11 @@ export function OnboardingFlowProvider({ children }: { children: ReactNode }) {
     void runFlow();
   }, [runFlow, userId]);
 
+  const handleMigrationComplete = useCallback(() => {
+    setActiveBlockingModal(null);
+    void runFlow();
+  }, [runFlow]);
+
   const handlePrivacyAccepted = useCallback(() => {
     setActiveBlockingModal(null);
     void runFlow();
@@ -163,7 +226,7 @@ export function OnboardingFlowProvider({ children }: { children: ReactNode }) {
 
   useEffect(() => {
     void runFlow();
-  }, [isAnonymous, onboardingQuery.data, runFlow, userId]);
+  }, [isAnonymous, runFlow, userId]);
 
   useEffect(() => {
     const onPrivacyAccepted = () => {
@@ -210,6 +273,12 @@ export function OnboardingFlowProvider({ children }: { children: ReactNode }) {
         onDismiss={handleClaimComplete}
         onClaimed={handleClaimComplete}
       />
+      <DexieMigrationModal
+        isOpen={activeBlockingModal === 'migration'}
+        localCount={migrationCounts.localCount}
+        missingCount={migrationCounts.missingCount}
+        onComplete={handleMigrationComplete}
+      />
     </OnboardingFlowContext.Provider>
   );
 }

src/contexts/RuntimeConfigContext.tsx

@@ -94,7 +94,7 @@ export function useFeatureFlag<K extends keyof RuntimeConfig>(key: K): RuntimeCo
 
 /**
  * Synchronous accessor for modules that are loaded before the React tree
- * mounts (for example config defaults). Falls back to the
+ * mounts (e.g. Dexie initialization, config defaults). Falls back to the
  * built-in defaults during SSR.
  */
 export function readRuntimeConfigSync(): RuntimeConfig {

src/contexts/TTSContext.tsx

@@ -33,7 +33,8 @@ import { useConfig } from '@/contexts/ConfigContext';
 import { useVoiceManagement } from '@/hooks/audio/useVoiceManagement';
 import { useMediaSession } from '@/hooks/audio/useMediaSession';
 import { useAudioContext } from '@/hooks/audio/useAudioContext';
-import { useDocumentProgress } from '@/hooks/useDocumentProgress';
+import { getLastDocumentLocation, setLastDocumentLocation } from '@/lib/client/dexie';
+import { getDocumentProgress, scheduleDocumentProgressSync } from '@/lib/client/api/user-state';
 import { withRetry, ensureTtsSegments } from '@/lib/client/api/audiobooks';
 import { preprocessSentenceForAudio } from '@/lib/shared/nlp';
 import {
@@ -81,7 +82,6 @@ import type {
   TTSSegmentManifestItem,
 } from '@/types/client';
 import { isStableEpubLocator } from '@/types/client';
-import { clearCachedAudioObjectUrls, getCachedAudioUrl } from '@/lib/client/cache/audio';
 
 /**
  * Resolves an EPUB segment's draft locator (typically `{ readerType: 'epub',
@@ -420,6 +420,8 @@ const TTSContext = createContext<TTSContextType | undefined>(undefined);
 export function TTSProvider({ children }: { children: ReactNode }): ReactElement {
   // Configuration context consumption
   const {
+    apiKey: openApiKey,
+    baseUrl: openApiBaseUrl,
     isLoading: configIsLoading,
     voiceSpeed,
     audioPlayerSpeed,
@@ -442,6 +444,8 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
   // Audio and voice management hooks
   const audioContext = useAudioContext();
   const { availableVoices, fetchVoices } = useVoiceManagement(
+    openApiKey,
+    openApiBaseUrl,
     configProviderRef,
     configProviderType,
     configTTSModel,
@@ -462,7 +466,6 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
     if (Array.isArray(id)) return id[0];
     return '';
   }, [id]);
-  const { query: progressQuery, schedule: scheduleProgress } = useDocumentProgress(documentId || undefined);
 
   const currentReaderType: ReaderType = useMemo(() => {
     if (pathname.startsWith('/epub/')) return 'epub';
@@ -726,7 +729,6 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
 
   useEffect(() => () => {
     clearWarmAudioCache();
-    clearCachedAudioObjectUrls();
   }, [clearWarmAudioCache]);
 
   const applyPlaybackRateToHowl = useCallback((howl: Howl | null) => {
@@ -1617,7 +1619,7 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
       setTTSModel(configTTSModel);
       setTTSInstructions(configTTSInstructions);
     }
-  }, [configIsLoading, updateVoiceAndSpeed, fetchVoices, configTTSModel, configTTSInstructions]);
+  }, [configIsLoading, openApiKey, openApiBaseUrl, updateVoiceAndSpeed, fetchVoices, configTTSModel, configTTSInstructions]);
 
   const preloadGenerationSignatureRef = useRef<string>('');
   useEffect(() => {
@@ -1764,8 +1766,12 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
 
     const reqHeaders: TTSRequestHeaders = {
       'Content-Type': 'application/json',
+      'x-openai-key': openApiKey || '',
       'x-tts-provider': configProviderRef,
     };
+    if (openApiBaseUrl) {
+      reqHeaders['x-openai-base-url'] = openApiBaseUrl;
+    }
 
     const retryOptions: TTSRetryOptions = {
       maxRetries: 2,
@@ -1908,6 +1914,8 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
     ttsModel,
     ttsInstructions,
     resolvedLanguage,
+    openApiKey,
+    openApiBaseUrl,
     configProviderRef,
     configProviderType,
     providerModelPolicy.supportsInstructions,
@@ -2036,13 +2044,7 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
         setCurrentSentenceAlignment(playbackSource.manifest.alignment);
         setCurrentWordIndex(null);
       }
-      const sourceUrl = useFallbackSource ? playbackSource.fallbackUrl : playbackSource.presignUrl;
-      const audioUrl = await getCachedAudioUrl({
-        audioKey: playbackSource.manifest.segmentId,
-        version: playbackSource.manifest.durationMs,
-        primaryUrl: sourceUrl,
-        fallbackUrl: playbackSource.fallbackUrl,
-      }).catch(() => sourceUrl);
+      const audioUrl = useFallbackSource ? playbackSource.fallbackUrl : playbackSource.presignUrl;
 
       // Force unload any previous Howl instance to free up resources
       if (activeHowl) {
@@ -2608,8 +2610,12 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
       activeAbortControllers.current.add(controller);
       const reqHeaders: TTSRequestHeaders = {
         'Content-Type': 'application/json',
+        'x-openai-key': openApiKey || '',
         'x-tts-provider': configProviderRef,
       };
+      if (openApiBaseUrl) {
+        reqHeaders['x-openai-base-url'] = openApiBaseUrl;
+      }
       const retryOptions: TTSRetryOptions = {
         maxRetries: 2,
         initialDelay: 300,
@@ -2897,8 +2903,12 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
     activeAbortControllers.current.add(controller);
     const reqHeaders: TTSRequestHeaders = {
       'Content-Type': 'application/json',
+      'x-openai-key': openApiKey || '',
       'x-tts-provider': configProviderRef,
     };
+    if (openApiBaseUrl) {
+      reqHeaders['x-openai-base-url'] = openApiBaseUrl;
+    }
 
     const retryOptions: TTSRetryOptions = {
       maxRetries: 2,
@@ -3016,6 +3026,8 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
     configProviderRef,
     configProviderType,
     ttsModel,
+    openApiKey,
+    openApiBaseUrl,
     providerModelPolicy.supportsInstructions,
     ttsInstructions,
     resolvedLanguage,
@@ -3385,9 +3397,13 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
     skipBackward,
   });
 
-  // Load the server-backed last location for EPUB/PDF/HTML.
+  // Load last location on mount for EPUB/PDF/HTML.
+  // Prefer server-backed progress when available, then fall back to local Dexie.
   useEffect(() => {
-    if (!id || !progressQuery.data?.location) return;
+    if (!id) return;
+
+    let cancelled = false;
+    const docId = id as string;
 
     const applyLocation = (lastLocation: string) => {
       if (isEPUB && locationChangeHandlerRef.current) {
@@ -3438,8 +3454,35 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
       }
     };
 
-    applyLocation(progressQuery.data.location);
-  }, [id, isEPUB, currentReaderType, progressQuery.data?.location]);
+    const load = async () => {
+      try {
+        const local = await getLastDocumentLocation(docId);
+        if (!cancelled && local) {
+          applyLocation(local);
+        }
+      } catch (error) {
+        console.warn('Error loading local last location:', error);
+      }
+
+      try {
+        const remote = await getDocumentProgress(docId);
+        if (!cancelled && remote?.location) {
+          await setLastDocumentLocation(docId, remote.location).catch((error) => {
+            console.warn('Error caching remote location locally:', error);
+          });
+          applyLocation(remote.location);
+        }
+      } catch (error) {
+        console.warn('Error loading remote progress:', error);
+      }
+    };
+
+    load();
+
+    return () => {
+      cancelled = true;
+    };
+  }, [id, isEPUB, currentReaderType]);
 
   // Save current position periodically for non-EPUB readers.
   useEffect(() => {
@@ -3448,7 +3491,10 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
         ? `html:${encodeURIComponent(String(currDocPage || 1))}:${currentIndex}`
         : `${currDocPageNumber}:${currentIndex}`;
       const timeoutId = setTimeout(() => {
-        scheduleProgress({
+        setLastDocumentLocation(id as string, location).catch(error => {
+          console.warn('Error saving non-EPUB location:', error);
+        });
+        scheduleDocumentProgressSync({
           documentId: id as string,
           readerType: currentReaderType,
           location,
@@ -3457,7 +3503,7 @@ export function TTSProvider({ children }: { children: ReactNode }): ReactElement
 
       return () => clearTimeout(timeoutId);
     }
-  }, [id, isEPUB, currDocPage, currDocPageNumber, currentIndex, sentences.length, currentReaderType, scheduleProgress]);
+  }, [id, isEPUB, currDocPage, currDocPageNumber, currentIndex, sentences.length, currentReaderType]);
 
   /**
    * Renders the TTS context provider with its children

src/hooks/audio/useVoiceManagement.ts

@@ -7,12 +7,16 @@ import { resolveTtsProviderModelPolicy } from '@/lib/shared/tts-provider-policy'
 
 /**
  * Custom hook for managing TTS voices
+ * @param apiKey OpenAI API key
+ * @param baseUrl OpenAI API base URL
  * @param providerRef TTS provider routing reference (built-in id or shared slug)
  * @param providerType Resolved provider type for capability/default logic
  * @param ttsModel TTS model name
  * @returns Object containing available voices and fetch function
  */
 export function useVoiceManagement(
+  apiKey: string | undefined,
+  baseUrl: string | undefined,
   providerRef: string | undefined,
   providerType: TtsProviderType | undefined,
   ttsModel: string | undefined
@@ -25,6 +29,8 @@ export function useVoiceManagement(
     try {
       console.log('Fetching voices...');
       const data = await getVoices({
+        'x-openai-key': apiKey || '',
+        'x-openai-base-url': baseUrl || '',
         'x-tts-provider': providerRef || 'openai',
         'x-tts-model': ttsModel || 'tts-1',
         'Content-Type': 'application/json',
@@ -50,7 +56,7 @@ export function useVoiceManagement(
         model: ttsModel || 'tts-1',
       }).defaultVoices);
     }
-  }, [providerRef, providerType, ttsModel]);
+  }, [apiKey, baseUrl, providerRef, providerType, ttsModel]);
 
   return { availableVoices, fetchVoices };
 }

src/hooks/epub/useEPUBAudiobook.ts

@@ -35,6 +35,8 @@ export function filterNonEmptySpineTextEntries<T extends { text: string }>(entri
 type UseEpubAudiobookParams = {
   bookRef: RefObject<Book | null>;
   tocRef: RefObject<NavItem[]>;
+  apiKey: string;
+  baseUrl: string;
   providerRef: string;
 };
 
@@ -59,6 +61,8 @@ type UseEpubAudiobookResult = {
 export function useEPUBAudiobook({
   bookRef,
   tocRef,
+  apiKey,
+  baseUrl,
   providerRef,
 }: UseEpubAudiobookParams): UseEpubAudiobookResult {
   const loadSpineSection = useCallback(async (href: string) => {
@@ -127,6 +131,8 @@ export function useEPUBAudiobook({
     try {
       return await runAudiobookGeneration({
         adapter: audiobookAdapter,
+        apiKey,
+        baseUrl,
         defaultProvider: providerRef,
         onProgress,
         signal,
@@ -139,7 +145,7 @@ export function useEPUBAudiobook({
       console.error('Error creating audiobook:', error);
       throw error;
     }
-  }, [audiobookAdapter, providerRef]);
+  }, [audiobookAdapter, apiKey, baseUrl, providerRef]);
 
   const regenerateChapter = useCallback(async (
     chapterIndex: number,
@@ -155,6 +161,8 @@ export function useEPUBAudiobook({
         bookId,
         format,
         signal,
+        apiKey,
+        baseUrl,
         defaultProvider: providerRef,
         settings,
       });
@@ -165,7 +173,7 @@ export function useEPUBAudiobook({
       console.error('Error regenerating chapter:', error);
       throw error;
     }
-  }, [audiobookAdapter, providerRef]);
+  }, [audiobookAdapter, apiKey, baseUrl, providerRef]);
 
   return {
     createFullAudioBook,

src/hooks/epub/useEPUBDocuments.ts

@@ -0,0 +1,53 @@
+'use client';
+
+import { useCallback } from 'react';
+import { useLiveQuery } from 'dexie-react-hooks';
+import { db } from '@/lib/client/dexie';
+import type { EPUBDocument } from '@/types/documents';
+import { sha256HexFromArrayBuffer } from '@/lib/client/sha256';
+
+export function useEPUBDocuments() {
+  const documents = useLiveQuery(
+    () => db['epub-documents'].toArray(),
+    [],
+    undefined,
+  );
+
+  const isLoading = documents === undefined;
+
+  const addDocument = useCallback(async (file: File): Promise<string> => {
+    const arrayBuffer = await file.arrayBuffer();
+    const id = await sha256HexFromArrayBuffer(arrayBuffer);
+
+    console.log('Original file size:', file.size);
+    console.log('ArrayBuffer size:', arrayBuffer.byteLength);
+
+    const newDoc: EPUBDocument = {
+      id,
+      type: 'epub',
+      name: file.name,
+      size: file.size,
+      lastModified: file.lastModified,
+      data: arrayBuffer,
+    };
+
+    await db['epub-documents'].put(newDoc);
+    return id;
+  }, []);
+
+  const removeDocument = useCallback(async (id: string): Promise<void> => {
+    await db['epub-documents'].delete(id);
+  }, []);
+
+  const clearDocuments = useCallback(async (): Promise<void> => {
+    await db['epub-documents'].clear();
+  }, []);
+
+  return {
+    documents: documents ?? [],
+    isLoading,
+    addDocument,
+    removeDocument,
+    clearDocuments,
+  };
+}

src/hooks/epub/useEPUBLocationController.ts

@@ -3,14 +3,33 @@
 import { useCallback, type MutableRefObject, type RefObject } from 'react';
 import type { Book, Rendition } from 'epubjs';
 
-import { useDocumentProgress } from '@/hooks/useDocumentProgress';
+import { setLastDocumentLocation } from '@/lib/client/dexie';
+import { scheduleDocumentProgressSync } from '@/lib/client/api/user-state';
 
-import {
-  isDirectionalEpubLocation,
-  shouldNavigateToDifferentCfi,
-  shouldPersistEpubLocation,
-  type EpubLocation,
-} from '@/lib/client/epub/location-controller';
+type EpubLocation = string | number;
+
+export function isDirectionalEpubLocation(location: EpubLocation): location is 'next' | 'prev' {
+  return location === 'next' || location === 'prev';
+}
+
+export function shouldNavigateToDifferentCfi(
+  location: EpubLocation,
+  currentStartCfi: string | undefined,
+): location is string {
+  return (
+    typeof location === 'string'
+    && !isDirectionalEpubLocation(location)
+    && !!currentStartCfi
+    && location !== currentStartCfi
+  );
+}
+
+export function shouldPersistEpubLocation(
+  documentId: string | undefined,
+  previousLocation: EpubLocation,
+): documentId is string {
+  return typeof documentId === 'string' && documentId.length > 0 && previousLocation !== 1;
+}
 
 type UseEpubLocationControllerParams = {
   documentId?: string;
@@ -35,7 +54,6 @@ export function useEPUBLocationController({
   renditionRef,
   locationRef,
 }: UseEpubLocationControllerParams): (location: EpubLocation) => void {
-  const { schedule: scheduleProgress } = useDocumentProgress(documentId);
   const safeRenditionNavigate = useCallback((navigation: 'next' | 'prev' | 'display', location?: string) => {
     const book = bookRef.current;
     const rendition = renditionRef.current;
@@ -115,9 +133,10 @@ export function useEPUBLocationController({
       return;
     }
 
-    // Save the server-backed location after the first real rendition update.
+    // Save the location to IndexedDB if not initial
     if (shouldPersistEpubLocation(documentId, locationRef.current)) {
-      scheduleProgress({
+      setLastDocumentLocation(documentId, location.toString());
+      scheduleDocumentProgressSync({
         documentId,
         readerType: 'epub',
         location: location.toString(),
@@ -141,11 +160,8 @@ export function useEPUBLocationController({
     safeRenditionNavigate,
     setIsEpub,
     shouldPauseRef,
-    scheduleProgress,
     skipToLocation,
   ]);
 
   return handleLocationChanged;
 }
-
-export { isDirectionalEpubLocation, shouldNavigateToDifferentCfi, shouldPersistEpubLocation };

src/hooks/html/useHTMLDocuments.ts

@@ -0,0 +1,52 @@
+'use client';
+
+import { useCallback } from 'react';
+import { useLiveQuery } from 'dexie-react-hooks';
+import { db } from '@/lib/client/dexie';
+import type { HTMLDocument } from '@/types/documents';
+import { sha256HexFromString } from '@/lib/client/sha256';
+
+export function useHTMLDocuments() {
+  const documents = useLiveQuery(
+    () => db['html-documents'].toArray(),
+    [],
+    undefined,
+  );
+
+  const isLoading = documents === undefined;
+
+  const addDocument = useCallback(async (file: File): Promise<string> => {
+    const buffer = await file.arrayBuffer();
+    const bytes = new Uint8Array(buffer);
+    const content = new TextDecoder().decode(bytes);
+    const id = await sha256HexFromString(content);
+
+    const newDoc: HTMLDocument = {
+      id,
+      type: 'html',
+      name: file.name,
+      size: file.size,
+      lastModified: file.lastModified,
+      data: content,
+    };
+
+    await db['html-documents'].put(newDoc);
+    return id;
+  }, []);
+
+  const removeDocument = useCallback(async (id: string): Promise<void> => {
+    await db['html-documents'].delete(id);
+  }, []);
+
+  const clearDocuments = useCallback(async (): Promise<void> => {
+    await db['html-documents'].clear();
+  }, []);
+
+  return {
+    documents: documents ?? [],
+    isLoading,
+    addDocument,
+    removeDocument,
+    clearDocuments,
+  };
+}

src/hooks/pdf/usePDFDocuments.ts

@@ -0,0 +1,50 @@
+'use client';
+
+import { useCallback } from 'react';
+import { useLiveQuery } from 'dexie-react-hooks';
+import { db } from '@/lib/client/dexie';
+import type { PDFDocument } from '@/types/documents';
+import { sha256HexFromArrayBuffer } from '@/lib/client/sha256';
+
+export function usePDFDocuments() {
+  const documents = useLiveQuery(
+    () => db['pdf-documents'].toArray(),
+    [],
+    undefined,
+  );
+
+  const isLoading = documents === undefined;
+
+  const addDocument = useCallback(async (file: File): Promise<string> => {
+    const arrayBuffer = await file.arrayBuffer();
+    const id = await sha256HexFromArrayBuffer(arrayBuffer);
+
+    const newDoc: PDFDocument = {
+      id,
+      type: 'pdf',
+      name: file.name,
+      size: file.size,
+      lastModified: file.lastModified,
+      data: arrayBuffer,
+    };
+
+    await db['pdf-documents'].put(newDoc);
+    return id;
+  }, []);
+
+  const removeDocument = useCallback(async (id: string): Promise<void> => {
+    await db['pdf-documents'].delete(id);
+  }, []);
+
+  const clearDocuments = useCallback(async (): Promise<void> => {
+    await db['pdf-documents'].clear();
+  }, []);
+
+  return {
+    documents: documents ?? [],
+    isLoading,
+    addDocument,
+    removeDocument,
+    clearDocuments,
+  };
+}

src/hooks/useDocumentLanguage.ts

@@ -1,31 +1,52 @@
 'use client';
 
-import { useCallback } from 'react';
+import { useCallback, useEffect, useState } from 'react';
 
+import { getDocumentSettings, putDocumentSettings } from '@/lib/client/api/documents';
 import { mergeDocumentSettings } from '@/lib/shared/document-settings';
 import { DEFAULT_DOCUMENT_SETTINGS, type DocumentSettings } from '@/types/document-settings';
-import { useDocumentSettings } from '@/hooks/useDocumentSettings';
 
 export function useDocumentLanguage(documentId: string | undefined): {
   language: string;
   updateLanguage: (language: string) => Promise<void>;
 } {
-  const { query, mutation } = useDocumentSettings(documentId);
-  const settings = mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, query.data?.settings);
+  const [settings, setSettings] = useState<DocumentSettings>(DEFAULT_DOCUMENT_SETTINGS);
+
+  useEffect(() => {
+    setSettings(DEFAULT_DOCUMENT_SETTINGS);
+    if (!documentId) return;
+
+    const controller = new AbortController();
+    void getDocumentSettings(documentId, { signal: controller.signal })
+      .then((response) => {
+        setSettings(mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, response.settings));
+      })
+      .catch((error) => {
+        if (error instanceof DOMException && error.name === 'AbortError') return;
+        console.warn('Failed to load document language, using automatic detection:', error);
+      });
+
+    return () => controller.abort();
+  }, [documentId]);
 
   const updateLanguage = useCallback(async (language: string): Promise<void> => {
     if (!documentId) return;
-    const next: DocumentSettings = mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, {
-      ...settings,
-      schemaVersion: 1,
-      language,
+    let next = DEFAULT_DOCUMENT_SETTINGS;
+    setSettings((prev) => {
+      next = mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, {
+        ...prev,
+        schemaVersion: 1,
+        language,
+      });
+      return next;
     });
     try {
-      await mutation.mutateAsync(next);
+      const response = await putDocumentSettings(documentId, next);
+      setSettings(mergeDocumentSettings(DEFAULT_DOCUMENT_SETTINGS, response.settings));
     } catch (error) {
       console.warn('Failed to persist document language:', error);
     }
-  }, [documentId, mutation, settings]);
+  }, [documentId]);
 
   return {
     language: settings.language ?? 'auto',

src/hooks/useDocumentProgress.ts

@@ -1,54 +0,0 @@
-'use client';
-
-import { useCallback, useEffect, useRef } from 'react';
-import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
-import { getDocumentProgress, putDocumentProgress } from '@/lib/client/api/user-state';
-import { queryKeys } from '@/lib/client/query-keys';
-import { useAuthSession } from '@/hooks/useAuthSession';
-import type { DocumentProgressRecord, ReaderType } from '@/types/user-state';
-
-export function useDocumentProgress(documentId: string | undefined) {
-  const { data: session, isPending } = useAuthSession();
-  const sessionId = session?.user?.id ?? 'no-session';
-  const key = queryKeys.progress(sessionId, documentId ?? '');
-  const queryClient = useQueryClient();
-  const timer = useRef<ReturnType<typeof setTimeout> | null>(null);
-  const query = useQuery({
-    queryKey: key,
-    queryFn: ({ signal }) => getDocumentProgress(documentId!, { signal }),
-    enabled: !isPending && !!documentId,
-  });
-  const mutation = useMutation({
-    mutationFn: putDocumentProgress,
-    onMutate: async (payload) => {
-      await queryClient.cancelQueries({ queryKey: key });
-      const previous = queryClient.getQueryData<DocumentProgressRecord | null>(key);
-      queryClient.setQueryData(key, {
-        documentId: payload.documentId,
-        readerType: payload.readerType,
-        location: payload.location,
-        progress: payload.progress ?? null,
-        clientUpdatedAtMs: Date.now(),
-        updatedAtMs: Date.now(),
-      });
-      return { previous };
-    },
-    onError: (_error, _payload, context) => queryClient.setQueryData(key, context?.previous),
-    onSuccess: (data) => queryClient.setQueryData(key, data),
-    onSettled: () => queryClient.invalidateQueries({ queryKey: key }),
-  });
-  const mutateProgress = mutation.mutate;
-  const schedule = useCallback((payload: {
-    documentId: string;
-    readerType: ReaderType;
-    location: string;
-    progress?: number | null;
-  }, debounceMs = 1000) => {
-    if (timer.current) clearTimeout(timer.current);
-    timer.current = setTimeout(() => mutateProgress(payload), debounceMs);
-  }, [mutateProgress]);
-  useEffect(() => () => {
-    if (timer.current) clearTimeout(timer.current);
-  }, []);
-  return { query, mutation, schedule };
-}

src/hooks/useDocumentSettings.ts

@@ -1,32 +0,0 @@
-'use client';
-
-import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
-import { getDocumentSettings, putDocumentSettings } from '@/lib/client/api/documents';
-import { queryKeys } from '@/lib/client/query-keys';
-import { useAuthSession } from '@/hooks/useAuthSession';
-import type { DocumentSettings } from '@/types/document-settings';
-
-export function useDocumentSettings(documentId: string | undefined) {
-  const { data: session, isPending } = useAuthSession();
-  const sessionId = session?.user?.id ?? 'no-session';
-  const key = queryKeys.documentSettings(sessionId, documentId ?? '');
-  const queryClient = useQueryClient();
-  const query = useQuery({
-    queryKey: key,
-    queryFn: ({ signal }) => getDocumentSettings(documentId!, { signal }),
-    enabled: !isPending && !!documentId,
-  });
-  const mutation = useMutation({
-    mutationFn: (settings: DocumentSettings) => putDocumentSettings(documentId!, settings),
-    onMutate: async (settings) => {
-      await queryClient.cancelQueries({ queryKey: key });
-      const previous = queryClient.getQueryData(key);
-      queryClient.setQueryData(key, { settings, clientUpdatedAtMs: Date.now(), hasStoredSettings: true });
-      return { previous };
-    },
-    onError: (_error, _settings, context) => queryClient.setQueryData(key, context?.previous),
-    onSuccess: (data) => queryClient.setQueryData(key, data),
-    onSettled: () => queryClient.invalidateQueries({ queryKey: key }),
-  });
-  return { query, mutation };
-}

src/hooks/useFolders.ts

@@ -1,103 +0,0 @@
-'use client';
-
-import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
-import { queryKeys } from '@/lib/client/query-keys';
-import { useAuthSession } from '@/hooks/useAuthSession';
-import type { BaseDocument } from '@/types/documents';
-
-export type ServerFolder = { id: string; name: string; position: number; createdAt?: number; updatedAt?: number };
-
-async function jsonRequest<T>(url: string, init?: RequestInit): Promise<T> {
-  const res = await fetch(url, init);
-  if (!res.ok) {
-    const data = await res.json().catch(() => null) as { error?: string } | null;
-    throw new Error(data?.error || 'Folder request failed');
-  }
-  return res.json() as Promise<T>;
-}
-
-export function useFolders() {
-  const { data: session, isPending } = useAuthSession();
-  const sessionId = session?.user?.id ?? 'no-session';
-  const foldersKey = queryKeys.folders(sessionId);
-  const documentsKey = queryKeys.documents(sessionId);
-  const queryClient = useQueryClient();
-  const query = useQuery({
-    queryKey: foldersKey,
-    queryFn: async ({ signal }) => (await jsonRequest<{ folders: ServerFolder[] }>('/api/folders', { signal })).folders,
-    enabled: !isPending,
-  });
-  const create = useMutation({
-    mutationFn: (input: { id?: string; name: string; documentIds?: string[] }) => jsonRequest<{ folder: ServerFolder }>('/api/folders', {
-      method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(input),
-    }),
-    onSuccess: ({ folder }, input) => {
-      queryClient.setQueryData<ServerFolder[]>(foldersKey, (rows = []) => [...rows, folder]);
-      if (input.documentIds?.length) queryClient.setQueryData<BaseDocument[]>(documentsKey, (rows = []) =>
-        rows.map((doc) => input.documentIds!.includes(doc.id) ? { ...doc, folderId: folder.id } : doc));
-    },
-    onSettled: () => Promise.all([
-      queryClient.invalidateQueries({ queryKey: foldersKey }),
-      queryClient.invalidateQueries({ queryKey: documentsKey }),
-    ]),
-  });
-  const move = useMutation({
-    mutationFn: (input: { documentIds: string[]; folderId: string | null }) => jsonRequest('/api/documents/folders', {
-      method: 'PATCH', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(input),
-    }),
-    onMutate: async (input) => {
-      await queryClient.cancelQueries({ queryKey: documentsKey });
-      const previous = queryClient.getQueryData<BaseDocument[]>(documentsKey);
-      queryClient.setQueryData<BaseDocument[]>(documentsKey, (rows = []) =>
-        rows.map((doc) => input.documentIds.includes(doc.id) ? { ...doc, folderId: input.folderId ?? undefined } : doc));
-      return { previous };
-    },
-    onError: (_error, _input, context) => queryClient.setQueryData(documentsKey, context?.previous),
-    onSettled: () => queryClient.invalidateQueries({ queryKey: documentsKey }),
-  });
-  const remove = useMutation({
-    mutationFn: (id: string) => jsonRequest(`/api/folders/${encodeURIComponent(id)}`, { method: 'DELETE' }),
-    onMutate: async (id) => {
-      await Promise.all([
-        queryClient.cancelQueries({ queryKey: foldersKey }),
-        queryClient.cancelQueries({ queryKey: documentsKey }),
-      ]);
-      const previousFolders = queryClient.getQueryData<ServerFolder[]>(foldersKey);
-      const previousDocuments = queryClient.getQueryData<BaseDocument[]>(documentsKey);
-      queryClient.setQueryData<ServerFolder[]>(foldersKey, (rows = []) => rows.filter((folder) => folder.id !== id));
-      queryClient.setQueryData<BaseDocument[]>(documentsKey, (rows = []) => rows.map((doc) => doc.folderId === id ? { ...doc, folderId: undefined } : doc));
-      return { previousFolders, previousDocuments };
-    },
-    onError: (_error, _id, context) => {
-      queryClient.setQueryData(foldersKey, context?.previousFolders);
-      queryClient.setQueryData(documentsKey, context?.previousDocuments);
-    },
-    onSettled: () => Promise.all([
-      queryClient.invalidateQueries({ queryKey: foldersKey }),
-      queryClient.invalidateQueries({ queryKey: documentsKey }),
-    ]),
-  });
-  const clear = useMutation({
-    mutationFn: () => jsonRequest('/api/folders', { method: 'DELETE' }),
-    onMutate: async () => {
-      await Promise.all([
-        queryClient.cancelQueries({ queryKey: foldersKey }),
-        queryClient.cancelQueries({ queryKey: documentsKey }),
-      ]);
-      const previousFolders = queryClient.getQueryData<ServerFolder[]>(foldersKey);
-      const previousDocuments = queryClient.getQueryData<BaseDocument[]>(documentsKey);
-      queryClient.setQueryData(foldersKey, []);
-      queryClient.setQueryData<BaseDocument[]>(documentsKey, (rows = []) => rows.map((doc) => ({ ...doc, folderId: undefined })));
-      return { previousFolders, previousDocuments };
-    },
-    onError: (_error, _input, context) => {
-      queryClient.setQueryData(foldersKey, context?.previousFolders);
-      queryClient.setQueryData(documentsKey, context?.previousDocuments);
-    },
-    onSettled: () => Promise.all([
-      queryClient.invalidateQueries({ queryKey: foldersKey }),
-      queryClient.invalidateQueries({ queryKey: documentsKey }),
-    ]),
-  });
-  return { query, create, move, remove, clear };
-}

src/hooks/useOnboardingState.ts

@@ -1,47 +0,0 @@
-'use client';
-
-import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
-import { queryKeys } from '@/lib/client/query-keys';
-import { useAuthSession } from '@/hooks/useAuthSession';
-
-export type OnboardingState = { privacyAcceptedAtMs: number | null; lastSeenAppVersion: string | null };
-
-async function fetchOnboarding(signal?: AbortSignal): Promise<OnboardingState> {
-  const res = await fetch('/api/user/state/onboarding', { signal });
-  if (!res.ok) throw new Error('Failed to load onboarding state');
-  return ((await res.json()) as { onboarding: OnboardingState }).onboarding;
-}
-
-export function useOnboardingState() {
-  const { data: session, isPending } = useAuthSession();
-  const sessionId = session?.user?.id ?? 'no-session';
-  const key = queryKeys.onboarding(sessionId);
-  const queryClient = useQueryClient();
-  const query = useQuery({ queryKey: key, queryFn: ({ signal }) => fetchOnboarding(signal), enabled: !isPending });
-  const mutation = useMutation({
-    mutationFn: async (patch: { privacyAccepted?: boolean; lastSeenAppVersion?: string }) => {
-      const res = await fetch('/api/user/state/onboarding', {
-        method: 'PATCH',
-        headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify(patch),
-      });
-      if (!res.ok) throw new Error('Failed to update onboarding state');
-      return ((await res.json()) as { onboarding: OnboardingState }).onboarding;
-    },
-    onMutate: async (patch) => {
-      await queryClient.cancelQueries({ queryKey: key });
-      const previous = queryClient.getQueryData<OnboardingState>(key);
-      queryClient.setQueryData<OnboardingState>(key, (current) => ({
-        privacyAcceptedAtMs: patch.privacyAccepted === undefined
-          ? current?.privacyAcceptedAtMs ?? null
-          : patch.privacyAccepted ? Date.now() : null,
-        lastSeenAppVersion: patch.lastSeenAppVersion ?? current?.lastSeenAppVersion ?? null,
-      }));
-      return { previous };
-    },
-    onError: (_error, _patch, context) => queryClient.setQueryData(key, context?.previous),
-    onSuccess: (data) => queryClient.setQueryData(key, data),
-    onSettled: () => queryClient.invalidateQueries({ queryKey: key }),
-  });
-  return { query, mutation };
-}

src/hooks/useUserPreferences.ts

@@ -1,29 +0,0 @@
-'use client';
-
-import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
-import { getUserPreferences, putUserPreferences } from '@/lib/client/api/user-state';
-import { queryKeys } from '@/lib/client/query-keys';
-import type { SyncedPreferencesPatch } from '@/types/user-state';
-
-export function useUserPreferences(sessionId: string, enabled: boolean) {
-  const queryClient = useQueryClient();
-  const key = queryKeys.preferences(sessionId);
-  const query = useQuery({ queryKey: key, queryFn: ({ signal }) => getUserPreferences({ signal }), enabled });
-  const mutation = useMutation({
-    mutationFn: (patch: SyncedPreferencesPatch) => putUserPreferences(patch),
-    onMutate: async (patch) => {
-      await queryClient.cancelQueries({ queryKey: key });
-      const previous = queryClient.getQueryData<Awaited<ReturnType<typeof getUserPreferences>>>(key);
-      queryClient.setQueryData(key, {
-        preferences: { ...(previous?.preferences ?? {}), ...patch },
-        clientUpdatedAtMs: Date.now(),
-        hasStoredPreferences: true,
-      });
-      return { previous };
-    },
-    onError: (_error, _patch, context) => queryClient.setQueryData(key, context?.previous),
-    onSuccess: (data) => queryClient.setQueryData(key, data),
-    onSettled: () => queryClient.invalidateQueries({ queryKey: key }),
-  });
-  return { query, mutation };
-}

src/lib/client/api/documents.ts

@@ -85,11 +85,7 @@ export async function listDocuments(options?: { ids?: string[]; signal?: AbortSi
 
 export async function getDocumentMetadata(id: string, options?: { signal?: AbortSignal }): Promise<BaseDocument | null> {
   const docs = await listDocuments({ ids: [id], signal: options?.signal });
-  const document = docs[0] ?? null;
-  if (document) {
-    void fetch(`/api/documents/${encodeURIComponent(id)}/opened`, { method: 'PUT' }).catch(() => {});
-  }
-  return document;
+  return docs[0] ?? null;
 }
 
 export class ParsedPdfNotReadyError extends Error {
@@ -443,13 +439,9 @@ export async function deleteDocuments(options?: { ids?: string[]; signal?: Abort
 }
 
 export async function downloadDocumentContent(id: string, options?: { signal?: AbortSignal }): Promise<ArrayBuffer> {
-  return (await fetchDocumentContentResponse(id, options)).arrayBuffer();
-}
-
-export async function fetchDocumentContentResponse(id: string, options?: { signal?: AbortSignal }): Promise<Response> {
   const fallbackUrl = `/api/documents/blob/get/fallback?id=${encodeURIComponent(id)}`;
 
-  const fetchFallback = async (): Promise<Response> => {
+  const fetchFallback = async (): Promise<ArrayBuffer> => {
     const res = await fetch(fallbackUrl, { signal: options?.signal });
     if (!res.ok) {
       const contentType = res.headers.get('content-type') || '';
@@ -459,7 +451,7 @@ export async function fetchDocumentContentResponse(id: string, options?: { signa
       }
       throw new Error(`Failed to download document (status ${res.status})`);
     }
-    return res;
+    return res.arrayBuffer();
   };
 
   try {
@@ -475,7 +467,7 @@ export async function fetchDocumentContentResponse(id: string, options?: { signa
       }
       throw new Error(`Failed to download document (status ${directRes.status})`);
     }
-    return directRes;
+    return directRes.arrayBuffer();
   } catch (error) {
     if (options?.signal?.aborted) throw error;
     return fetchFallback();
@@ -516,7 +508,6 @@ export type DocumentPreviewReady = {
   fallbackUrl: string;
   presignUrl: string;
   directUrl?: string;
-  previewVersion: string;
 };
 
 export type DocumentPreviewStatus = DocumentPreviewPending | DocumentPreviewReady;
@@ -565,14 +556,12 @@ export async function getDocumentPreviewStatus(
       fallbackUrl?: string;
       presignUrl?: string;
       directUrl?: string;
-      previewVersion?: string;
     } | null;
     return {
       kind: 'ready',
       fallbackUrl: data?.fallbackUrl || documentPreviewFallbackUrl(id),
       presignUrl: data?.presignUrl || documentPreviewPresignUrl(id),
       directUrl: data?.directUrl,
-      previewVersion: data?.previewVersion || '',
     };
   }
 
@@ -617,3 +606,4 @@ export async function importUrl(
 
   return (await res.json()) as { title: string; content: string };
 }
+

src/lib/client/api/user-state.ts

@@ -78,6 +78,102 @@ export async function postChangelogVersionCheck(
   return (await res.json()) as ChangelogVersionCheckResponse;
 }
 
+type PendingPreferenceSync = {
+  patch: SyncedPreferencesPatch;
+  timer: ReturnType<typeof setTimeout> | null;
+  sessionId: string | null;
+};
+
+const pendingPreferenceSync: PendingPreferenceSync = {
+  patch: {},
+  timer: null,
+  sessionId: null,
+};
+
+let activeSyncController: AbortController | null = null;
+
+/**
+ * Cancel any pending debounced preference sync and abort in-flight requests.
+ * Call this on session change / sign-out to prevent cross-account writes.
+ */
+export function cancelPendingPreferenceSync(): void {
+  if (pendingPreferenceSync.timer) {
+    clearTimeout(pendingPreferenceSync.timer);
+    pendingPreferenceSync.timer = null;
+  }
+  pendingPreferenceSync.patch = {};
+  pendingPreferenceSync.sessionId = null;
+
+  if (activeSyncController) {
+    activeSyncController.abort();
+    activeSyncController = null;
+  }
+}
+
+export function scheduleUserPreferencesSync(
+  patch: SyncedPreferencesPatch,
+  sessionId: string,
+  debounceMs: number = 600,
+): void {
+  Object.assign(pendingPreferenceSync.patch, sanitizePreferencesPatch(patch));
+  pendingPreferenceSync.sessionId = sessionId;
+
+  if (pendingPreferenceSync.timer) {
+    clearTimeout(pendingPreferenceSync.timer);
+  }
+
+  const capturedSessionId = sessionId;
+
+  pendingPreferenceSync.timer = setTimeout(async () => {
+    // If the session changed between scheduling and firing, discard.
+    if (pendingPreferenceSync.sessionId !== capturedSessionId) return;
+
+    const payload = { ...pendingPreferenceSync.patch };
+    pendingPreferenceSync.patch = {};
+    pendingPreferenceSync.timer = null;
+    if (Object.keys(payload).length === 0) return;
+
+    // Abort any previous in-flight sync and create a fresh controller.
+    if (activeSyncController) activeSyncController.abort();
+    activeSyncController = new AbortController();
+
+    try {
+      await putUserPreferences(payload, { signal: activeSyncController.signal });
+    } catch (error) {
+      if ((error as Error)?.name === 'AbortError') return;
+      console.warn('Failed to sync user preferences:', error);
+    } finally {
+      activeSyncController = null;
+    }
+  }, debounceMs);
+}
+
+/**
+ * Immediately send any pending debounced preference patch and await the result.
+ * Use this when the user explicitly saves: we want the server write to complete
+ * (and surface failures) instead of silently relying on the debounce timer, which
+ * can be lost if the page is reloaded inside the debounce window.
+ */
+export async function flushUserPreferencesSync(): Promise<void> {
+  if (pendingPreferenceSync.timer) {
+    clearTimeout(pendingPreferenceSync.timer);
+    pendingPreferenceSync.timer = null;
+  }
+
+  const payload = { ...pendingPreferenceSync.patch };
+  pendingPreferenceSync.patch = {};
+  if (Object.keys(payload).length === 0) return;
+
+  if (activeSyncController) activeSyncController.abort();
+  activeSyncController = new AbortController();
+
+  try {
+    await putUserPreferences(payload, { signal: activeSyncController.signal });
+  } finally {
+    activeSyncController = null;
+  }
+}
+
 export async function getDocumentProgress(
   documentId: string,
   options?: { signal?: AbortSignal },
@@ -120,3 +216,56 @@ export async function putDocumentProgress(payload: {
   const data = (await res.json()) as ProgressResponse;
   return data.progress ?? null;
 }
+
+type PendingProgressSync = {
+  payload: {
+    documentId: string;
+    readerType: ReaderType;
+    location: string;
+    progress: number | null;
+  };
+  timer: ReturnType<typeof setTimeout> | null;
+};
+
+const pendingProgressByDoc = new Map<string, PendingProgressSync>();
+
+export function scheduleDocumentProgressSync(
+  payload: {
+    documentId: string;
+    readerType: ReaderType;
+    location: string;
+    progress?: number | null;
+  },
+  debounceMs: number = 1000,
+): void {
+  const existing = pendingProgressByDoc.get(payload.documentId);
+  if (existing?.timer) {
+    clearTimeout(existing.timer);
+  }
+
+  const next: PendingProgressSync = {
+    payload: {
+      documentId: payload.documentId,
+      readerType: payload.readerType,
+      location: payload.location,
+      progress: payload.progress ?? null,
+    },
+    timer: null,
+  };
+
+  next.timer = setTimeout(async () => {
+    pendingProgressByDoc.delete(payload.documentId);
+    try {
+      await putDocumentProgress({
+        documentId: next.payload.documentId,
+        readerType: next.payload.readerType,
+        location: next.payload.location,
+        progress: next.payload.progress,
+      });
+    } catch (error) {
+      console.warn('Failed to sync document progress:', error);
+    }
+  }, debounceMs);
+
+  pendingProgressByDoc.set(payload.documentId, next);
+}

src/lib/client/audiobooks/pipeline.ts

@@ -29,6 +29,8 @@ export interface AudiobookSourceAdapter {
 
 interface RunAudiobookGenerationOptions {
   adapter: AudiobookSourceAdapter;
+  apiKey: string;
+  baseUrl: string;
   defaultProvider: string;
   onProgress: (progress: number) => void;
   signal?: AbortSignal;
@@ -45,6 +47,8 @@ interface RegenerateAudiobookChapterOptions {
   bookId: string;
   format: TTSAudiobookFormat;
   signal: AbortSignal;
+  apiKey: string;
+  baseUrl: string;
   defaultProvider: string;
   settings?: AudiobookGenerationSettings;
   retryOptions?: TTSRetryOptions;
@@ -67,10 +71,14 @@ function resolveAudiobookRequestSettings(
 }
 
 function buildAudiobookRequestHeaders(
+  apiKey: string,
+  baseUrl: string,
   effectiveProvider: string,
 ): TTSRequestHeaders {
   return {
     'Content-Type': 'application/json',
+    'x-openai-key': apiKey,
+    'x-openai-base-url': baseUrl,
     'x-tts-provider': effectiveProvider,
   };
 }
@@ -87,6 +95,8 @@ function createAudiobookAbortError(): Error {
 
 export async function runAudiobookGeneration({
   adapter,
+  apiKey,
+  baseUrl,
   defaultProvider,
   onProgress,
   signal,
@@ -110,7 +120,7 @@ export async function runAudiobookGeneration({
   }
 
   const { effectiveProviderRef, effectiveFormat } = resolveAudiobookRequestSettings(settings, defaultProvider, format);
-  const reqHeaders = buildAudiobookRequestHeaders(effectiveProviderRef);
+  const reqHeaders = buildAudiobookRequestHeaders(apiKey, baseUrl, effectiveProviderRef);
   let processedLength = 0;
   let bookId = providedBookId;
 
@@ -211,6 +221,8 @@ export async function regenerateAudiobookChapter({
   bookId,
   format,
   signal,
+  apiKey,
+  baseUrl,
   defaultProvider,
   settings,
   retryOptions = {
@@ -226,7 +238,7 @@ export async function regenerateAudiobookChapter({
   }
 
   const { effectiveProviderRef, effectiveFormat } = resolveAudiobookRequestSettings(settings, defaultProvider, format);
-  const reqHeaders = buildAudiobookRequestHeaders(effectiveProviderRef);
+  const reqHeaders = buildAudiobookRequestHeaders(apiKey, baseUrl, effectiveProviderRef);
 
   return withRetry(
     async () => {

src/lib/client/cache/audio.ts

@@ -1,28 +0,0 @@
-import { audioBlobCacheKey, getCachedBlob } from '@/lib/client/cache/blob-cache';
-
-const objectUrls = new Map<string, string>();
-
-export async function getCachedAudioUrl(input: {
-  audioKey: string;
-  version: string | number;
-  primaryUrl: string | null;
-  fallbackUrl: string | null;
-}): Promise<string> {
-  const key = audioBlobCacheKey(input.audioKey, input.version);
-  const existing = objectUrls.get(key);
-  if (existing) return existing;
-  const response = await getCachedBlob(key, async () => {
-    const primary = input.primaryUrl ? await fetch(input.primaryUrl).catch(() => null) : null;
-    if (primary?.ok) return primary;
-    if (!input.fallbackUrl) return primary ?? new Response(null, { status: 404 });
-    return fetch(input.fallbackUrl);
-  });
-  const url = URL.createObjectURL(await response.blob());
-  objectUrls.set(key, url);
-  return url;
-}
-
-export function clearCachedAudioObjectUrls(): void {
-  for (const url of objectUrls.values()) URL.revokeObjectURL(url);
-  objectUrls.clear();
-}

src/lib/client/cache/blob-cache.ts

@@ -1,60 +0,0 @@
-const BLOB_CACHE_NAME = 'openreader-blobs-v1';
-
-function canUseCacheStorage(): boolean {
-  return typeof window !== 'undefined' && typeof caches !== 'undefined';
-}
-
-export async function getCachedBlob(
-  stableKey: string,
-  fetchSource: () => Promise<Response>,
-): Promise<Response> {
-  let cache: Cache | null = null;
-  if (canUseCacheStorage()) {
-    try {
-      cache = await caches.open(BLOB_CACHE_NAME);
-      const cached = await cache.match(stableKey);
-      if (cached) return cached;
-    } catch {
-      cache = null;
-    }
-  }
-
-  const response = await fetchSource();
-  if (!response.ok) throw new Error(`Blob fetch failed: ${response.status}`);
-
-  if (cache && response.status === 200 && response.type !== 'opaque' && !response.headers.has('Content-Range')) {
-    await cache.put(stableKey, response.clone()).catch(() => {});
-  }
-  return response;
-}
-
-export async function putCachedBlob(stableKey: string, response: Response): Promise<void> {
-  if (!canUseCacheStorage() || !response.ok || response.status !== 200 || response.type === 'opaque') return;
-  const cache = await caches.open(BLOB_CACHE_NAME).catch(() => null);
-  await cache?.put(stableKey, response.clone()).catch(() => {});
-}
-
-export async function evictCachedBlobPrefix(prefix: string): Promise<void> {
-  if (!canUseCacheStorage()) return;
-  const cache = await caches.open(BLOB_CACHE_NAME).catch(() => null);
-  if (!cache) return;
-  const keys = await cache.keys().catch(() => []);
-  await Promise.allSettled(keys.filter((request) => new URL(request.url).pathname.startsWith(prefix)).map((request) => cache.delete(request)));
-}
-
-export async function clearBlobCache(): Promise<void> {
-  if (!canUseCacheStorage()) return;
-  await caches.delete(BLOB_CACHE_NAME).catch(() => {});
-}
-
-export function documentBlobCacheKey(documentId: string, contentVersion: string): string {
-  return `/openreader-cache/documents/${encodeURIComponent(documentId)}/${encodeURIComponent(contentVersion)}`;
-}
-
-export function previewBlobCacheKey(documentId: string, previewVersion: string | number): string {
-  return `/openreader-cache/previews/${encodeURIComponent(documentId)}/${encodeURIComponent(String(previewVersion))}`;
-}
-
-export function audioBlobCacheKey(audioKey: string, version: string | number): string {
-  return `/openreader-cache/audio/${encodeURIComponent(audioKey)}/${encodeURIComponent(String(version))}`;
-}

src/lib/client/cache/documents.ts

@@ -1,50 +1,152 @@
 import type { BaseDocument, EPUBDocument, HTMLDocument, PDFDocument } from '@/types/documents';
-import { fetchDocumentContentResponse } from '@/lib/client/api/documents';
-import {
-  clearBlobCache,
-  documentBlobCacheKey,
-  evictCachedBlobPrefix,
-  getCachedBlob,
-  putCachedBlob,
-} from '@/lib/client/cache/blob-cache';
+import { downloadDocumentContent } from '@/lib/client/api/documents';
 
-function stableKey(meta: BaseDocument): string {
-  return documentBlobCacheKey(meta.id, meta.contentVersion || meta.id);
-}
+export type DocumentCacheBackend = {
+  get: (meta: BaseDocument) => Promise<PDFDocument | EPUBDocument | HTMLDocument | null>;
+  putPdf: (meta: BaseDocument, data: ArrayBuffer) => Promise<void>;
+  putEpub: (meta: BaseDocument, data: ArrayBuffer) => Promise<void>;
+  putHtml: (meta: BaseDocument, data: string) => Promise<void>;
+  download: (id: string, options?: { signal?: AbortSignal }) => Promise<ArrayBuffer>;
+  decodeText: (buffer: ArrayBuffer) => string;
+};
 
-async function readDocument(meta: BaseDocument, response: Response): Promise<PDFDocument | EPUBDocument | HTMLDocument> {
-  if (meta.type === 'html') {
-    return { ...meta, type: 'html', data: await response.text() };
-  }
-  const data = await response.arrayBuffer();
-  if (meta.type === 'epub') return { ...meta, type: 'epub', data };
-  return { ...meta, type: 'pdf', data };
-}
-
-export async function ensureCachedDocument(
+export async function ensureCachedDocumentCore(
   meta: BaseDocument,
+  backend: DocumentCacheBackend,
   options?: { signal?: AbortSignal },
 ): Promise<PDFDocument | EPUBDocument | HTMLDocument> {
-  if (meta.type !== 'pdf' && meta.type !== 'epub' && meta.type !== 'html') {
-    throw new Error(`Unsupported cached document type: ${meta.type}`);
+  const cached = await backend.get(meta);
+  if (cached) return cached;
+
+  const buffer = await backend.download(meta.id, { signal: options?.signal });
+
+  if (meta.type === 'pdf') {
+    await backend.putPdf(meta, buffer);
+    const after = await backend.get(meta);
+    if (!after || after.type !== 'pdf') throw new Error('Failed to cache PDF');
+    return after;
   }
-  const response = await getCachedBlob(stableKey(meta), () => fetchDocumentContentResponse(meta.id, options));
-  return readDocument(meta, response);
+
+  if (meta.type === 'epub') {
+    await backend.putEpub(meta, buffer);
+    const after = await backend.get(meta);
+    if (!after || after.type !== 'epub') throw new Error('Failed to cache EPUB');
+    return after;
+  }
+
+  const decoded = backend.decodeText(buffer);
+  await backend.putHtml(meta, decoded);
+  const after = await backend.get(meta);
+  if (!after || after.type !== 'html') throw new Error('Failed to cache HTML');
+  return after;
 }
 
-export async function cacheStoredDocumentFromBytes(stored: BaseDocument, bytes: ArrayBuffer): Promise<void> {
-  const type = stored.type === 'pdf'
-    ? 'application/pdf'
-    : stored.type === 'epub'
-      ? 'application/epub+zip'
-      : 'text/plain; charset=utf-8';
-  await putCachedBlob(stableKey(stored), new Response(bytes, { status: 200, headers: { 'Content-Type': type } }));
+export async function getCachedPdf(id: string): Promise<PDFDocument | null> {
+  const { getPdfDocument } = await import('@/lib/client/dexie');
+  return (await getPdfDocument(id)) ?? null;
+}
+
+export async function putCachedPdf(meta: BaseDocument, data: ArrayBuffer): Promise<void> {
+  const { addPdfDocument } = await import('@/lib/client/dexie');
+  await addPdfDocument({
+    id: meta.id,
+    type: 'pdf',
+    name: meta.name,
+    size: meta.size,
+    lastModified: meta.lastModified,
+    data,
+  });
+}
+
+export async function evictCachedPdf(id: string): Promise<void> {
+  const { removePdfDocument } = await import('@/lib/client/dexie');
+  await removePdfDocument(id);
+}
+
+export async function getCachedEpub(id: string): Promise<EPUBDocument | null> {
+  const { getEpubDocument } = await import('@/lib/client/dexie');
+  return (await getEpubDocument(id)) ?? null;
+}
+
+export async function putCachedEpub(meta: BaseDocument, data: ArrayBuffer): Promise<void> {
+  const { addEpubDocument } = await import('@/lib/client/dexie');
+  await addEpubDocument({
+    id: meta.id,
+    type: 'epub',
+    name: meta.name,
+    size: meta.size,
+    lastModified: meta.lastModified,
+    data,
+  });
+}
+
+export async function evictCachedEpub(id: string): Promise<void> {
+  const { removeEpubDocument } = await import('@/lib/client/dexie');
+  await removeEpubDocument(id);
+}
+
+export async function getCachedHtml(id: string): Promise<HTMLDocument | null> {
+  const { getHtmlDocument } = await import('@/lib/client/dexie');
+  return (await getHtmlDocument(id)) ?? null;
+}
+
+export async function putCachedHtml(meta: BaseDocument, data: string): Promise<void> {
+  const { addHtmlDocument } = await import('@/lib/client/dexie');
+  await addHtmlDocument({
+    id: meta.id,
+    type: 'html',
+    name: meta.name,
+    size: meta.size,
+    lastModified: meta.lastModified,
+    data,
+  });
+}
+
+export async function evictCachedHtml(id: string): Promise<void> {
+  const { removeHtmlDocument } = await import('@/lib/client/dexie');
+  await removeHtmlDocument(id);
 }
 
 export async function evictCachedDocument(id: string): Promise<void> {
-  await evictCachedBlobPrefix(`/openreader-cache/documents/${encodeURIComponent(id)}/`);
+  await Promise.allSettled([evictCachedPdf(id), evictCachedEpub(id), evictCachedHtml(id)]);
 }
 
 export async function clearDocumentCache(): Promise<void> {
-  await clearBlobCache();
+  const { clearPdfDocuments, clearEpubDocuments, clearHtmlDocuments } = await import('@/lib/client/dexie');
+  await Promise.all([clearPdfDocuments(), clearEpubDocuments(), clearHtmlDocuments()]);
+}
+
+export async function cacheStoredDocumentFromBytes(stored: BaseDocument, bytes: ArrayBuffer): Promise<void> {
+  if (stored.type === 'pdf') {
+    await putCachedPdf(stored, bytes);
+    return;
+  }
+  if (stored.type === 'epub') {
+    await putCachedEpub(stored, bytes);
+    return;
+  }
+  if (stored.type === 'html') {
+    const decoded = new TextDecoder().decode(new Uint8Array(bytes));
+    await putCachedHtml(stored, decoded);
+  }
+}
+
+export async function ensureCachedDocument(meta: BaseDocument, options?: { signal?: AbortSignal }): Promise<PDFDocument | EPUBDocument | HTMLDocument> {
+  return ensureCachedDocumentCore(
+    meta,
+    {
+      get: async (m) => {
+        const { getPdfDocument, getEpubDocument, getHtmlDocument } = await import('@/lib/client/dexie');
+        if (m.type === 'pdf') return (await getPdfDocument(m.id)) ?? null;
+        if (m.type === 'epub') return (await getEpubDocument(m.id)) ?? null;
+        return (await getHtmlDocument(m.id)) ?? null;
+      },
+      putPdf: putCachedPdf,
+      putEpub: putCachedEpub,
+      putHtml: putCachedHtml,
+      download: downloadDocumentContent,
+      decodeText: (buffer) => new TextDecoder().decode(new Uint8Array(buffer)),
+    },
+    options,
+  );
 }

src/lib/client/cache/previews.ts

@@ -1,11 +1,24 @@
+import {
+  clearDocumentPreviewCache as clearPersistedDocumentPreviewCache,
+  getDocumentPreviewCache,
+  putDocumentPreviewCache,
+  removeDocumentPreviewCache,
+} from '@/lib/client/dexie';
 import { documentPreviewFallbackUrl, documentPreviewPresignUrl } from '@/lib/client/api/documents';
-import { clearBlobCache, getCachedBlob, previewBlobCacheKey } from '@/lib/client/cache/blob-cache';
 
 const inMemoryPreviewUrlCache = new Map<string, string>();
 const inFlightPreviewPrime = new Map<string, Promise<string | null>>();
+const inFlightPersistedPreviewUrl = new Map<string, Promise<string | null>>();
+const PREVIEW_CACHE_SCHEMA_VERSION = 4;
 
 function revokeIfBlobUrl(url: string | null | undefined): void {
-  if (url?.startsWith('blob:')) URL.revokeObjectURL(url);
+  if (!url) return;
+  if (!url.startsWith('blob:')) return;
+  try {
+    URL.revokeObjectURL(url);
+  } catch {
+    // ignore
+  }
 }
 
 export function getInMemoryDocumentPreviewUrl(cacheKey: string): string | null {
@@ -14,62 +27,131 @@ export function getInMemoryDocumentPreviewUrl(cacheKey: string): string | null {
 
 export function setInMemoryDocumentPreviewUrl(cacheKey: string, url: string): void {
   const prev = inMemoryPreviewUrlCache.get(cacheKey);
-  if (prev && prev !== url) revokeIfBlobUrl(prev);
+  if (prev && prev !== url) {
+    revokeIfBlobUrl(prev);
+  }
   inMemoryPreviewUrlCache.set(cacheKey, url);
 }
 
 export function clearInMemoryDocumentPreviewCache(): void {
-  for (const value of inMemoryPreviewUrlCache.values()) revokeIfBlobUrl(value);
+  for (const value of inMemoryPreviewUrlCache.values()) {
+    revokeIfBlobUrl(value);
+  }
   inMemoryPreviewUrlCache.clear();
-}
-
-async function fetchPreviewSource(docId: string, signal?: AbortSignal): Promise<Response> {
-  const options = { signal, cache: 'no-store' as const };
-  const direct = await fetch(documentPreviewPresignUrl(docId), options).catch(() => null);
-  if (direct?.ok) return direct;
-  return fetch(documentPreviewFallbackUrl(docId), options);
+  inFlightPersistedPreviewUrl.clear();
 }
 
 export async function getPersistedDocumentPreviewUrl(
   docId: string,
-  previewVersion: string | number,
+  lastModified: number,
   cacheKey: string,
 ): Promise<string | null> {
-  return primeDocumentPreviewCache(docId, previewVersion, cacheKey);
+  const cachedUrl = getInMemoryDocumentPreviewUrl(cacheKey);
+  if (cachedUrl) return cachedUrl;
+
+  const persistedKey = `${cacheKey}:${Number(lastModified)}`;
+  const existing = inFlightPersistedPreviewUrl.get(persistedKey);
+  if (existing) {
+    return existing;
+  }
+
+  const promise = (async (): Promise<string | null> => {
+    const row = await getDocumentPreviewCache(docId);
+    if (!row) return null;
+
+    if (Number((row as { previewVersion?: number }).previewVersion ?? 1) !== PREVIEW_CACHE_SCHEMA_VERSION) {
+      await removeDocumentPreviewCache(docId).catch(() => {});
+      return null;
+    }
+
+    if (Number(row.lastModified) !== Number(lastModified)) {
+      await removeDocumentPreviewCache(docId).catch(() => {});
+      return null;
+    }
+
+    const latestCachedUrl = getInMemoryDocumentPreviewUrl(cacheKey);
+    if (latestCachedUrl) return latestCachedUrl;
+
+    const contentType = row.contentType || 'image/jpeg';
+    const bytes = row.data;
+    if (!(bytes instanceof ArrayBuffer) || bytes.byteLength === 0) {
+      await removeDocumentPreviewCache(docId).catch(() => {});
+      return null;
+    }
+
+    const url = URL.createObjectURL(new Blob([bytes], { type: contentType }));
+    setInMemoryDocumentPreviewUrl(cacheKey, url);
+    return url;
+  })();
+
+  inFlightPersistedPreviewUrl.set(persistedKey, promise);
+  try {
+    return await promise;
+  } finally {
+    if (inFlightPersistedPreviewUrl.get(persistedKey) === promise) {
+      inFlightPersistedPreviewUrl.delete(persistedKey);
+    }
+  }
 }
 
 export async function primeDocumentPreviewCache(
   docId: string,
-  previewVersion: string | number,
+  lastModified: number,
   cacheKey: string,
   options?: { signal?: AbortSignal },
 ): Promise<string | null> {
-  const memory = getInMemoryDocumentPreviewUrl(cacheKey);
-  if (memory) return memory;
-  const primeKey = `${docId}:${previewVersion}`;
-  const existing = inFlightPreviewPrime.get(primeKey);
+  const primeKey = `${cacheKey}:${Number(lastModified)}`;
+  const existingPrime = inFlightPreviewPrime.get(primeKey);
+  if (existingPrime) {
+    return existingPrime;
+  }
+
+  const promise = (async (): Promise<string | null> => {
+  const existing = await getPersistedDocumentPreviewUrl(docId, lastModified, cacheKey);
   if (existing) return existing;
-  const promise = (async () => {
-    const response = await getCachedBlob(
-      previewBlobCacheKey(docId, previewVersion),
-      () => fetchPreviewSource(docId, options?.signal),
-    ).catch(() => null);
-    if (!response?.ok) return null;
-    const blob = await response.blob();
-    if (blob.size === 0) return null;
-    const url = URL.createObjectURL(blob);
-    setInMemoryDocumentPreviewUrl(cacheKey, url);
-    return url;
+
+  const fetchOptions = {
+    signal: options?.signal,
+    cache: 'no-store' as const,
+  };
+
+  // Prefer presign path for priming so healthy direct object access avoids proxy load.
+  let res = await fetch(documentPreviewPresignUrl(docId), fetchOptions).catch(() => null);
+  if (!res || !res.ok) {
+    res = await fetch(documentPreviewFallbackUrl(docId), fetchOptions).catch(() => null);
+  }
+  if (!res || !res.ok) return null;
+
+  const blob = await res.blob();
+  const bytes = await blob.arrayBuffer();
+  if (bytes.byteLength === 0) return null;
+
+  const contentType = blob.type || 'image/jpeg';
+  await putDocumentPreviewCache({
+    docId,
+    lastModified: Number(lastModified),
+    contentType,
+    data: bytes,
+    cachedAt: Date.now(),
+    previewVersion: PREVIEW_CACHE_SCHEMA_VERSION,
+  });
+
+  const url = URL.createObjectURL(new Blob([bytes], { type: contentType }));
+  setInMemoryDocumentPreviewUrl(cacheKey, url);
+  return url;
   })();
+
   inFlightPreviewPrime.set(primeKey, promise);
   try {
     return await promise;
   } finally {
-    inFlightPreviewPrime.delete(primeKey);
+    if (inFlightPreviewPrime.get(primeKey) === promise) {
+      inFlightPreviewPrime.delete(primeKey);
+    }
   }
 }
 
 export async function clearAllDocumentPreviewCaches(): Promise<void> {
   clearInMemoryDocumentPreviewCache();
-  await clearBlobCache();
+  await clearPersistedDocumentPreviewCache();
 }

src/lib/client/epub/location-controller.ts

@@ -1,22 +0,0 @@
-export type EpubLocation = string | number;
-
-export function isDirectionalEpubLocation(location: EpubLocation): location is 'next' | 'prev' {
-  return location === 'next' || location === 'prev';
-}
-
-export function shouldNavigateToDifferentCfi(
-  location: EpubLocation,
-  currentStartCfi: string | undefined,
-): location is string {
-  return typeof location === 'string'
-    && !isDirectionalEpubLocation(location)
-    && !!currentStartCfi
-    && location !== currentStartCfi;
-}
-
-export function shouldPersistEpubLocation(
-  documentId: string | undefined,
-  previousLocation: EpubLocation,
-): documentId is string {
-  return typeof documentId === 'string' && documentId.length > 0 && previousLocation !== 1;
-}

src/lib/client/onboarding-flow.ts

@@ -1,10 +1,11 @@
-export type OnboardingStep = 'privacy' | 'claim' | 'changelog' | 'done';
+export type OnboardingStep = 'privacy' | 'claim' | 'migration' | 'changelog' | 'done';
 
 export type OnboardingStepSnapshot = {
   privacyRequired: boolean;
   privacyAccepted: boolean;
   claimEligible: boolean;
   claimHasData: boolean;
+  migrationRequired: boolean;
   changelogPending: boolean;
 };
 
@@ -17,6 +18,10 @@ export function resolveNextOnboardingStep(snapshot: OnboardingStepSnapshot): Onb
     return 'claim';
   }
 
+  if (snapshot.migrationRequired) {
+    return 'migration';
+  }
+
   if (snapshot.changelogPending) {
     return 'changelog';
   }

src/lib/client/query-keys.ts

@@ -1,15 +0,0 @@
-export const queryKeys = {
-  documents: (sessionId: string) => ['documents', sessionId] as const,
-  document: (sessionId: string, documentId: string) => ['documents', sessionId, documentId] as const,
-  preferences: (sessionId: string) => ['preferences', sessionId] as const,
-  progress: (sessionId: string, documentId: string) => ['progress', sessionId, documentId] as const,
-  documentSettings: (sessionId: string, documentId: string) => ['document-settings', sessionId, documentId] as const,
-  onboarding: (sessionId: string) => ['onboarding', sessionId] as const,
-  folders: (sessionId: string) => ['folders', sessionId] as const,
-  audiobook: (sessionId: string, bookId: string) => ['audiobook', sessionId, bookId] as const,
-  ttsManifest: (sessionId: string, documentId: string) => ['tts-manifest', sessionId, documentId] as const,
-  parsedDocument: (sessionId: string, documentId: string) => ['parsed-document', sessionId, documentId] as const,
-  claimCounts: (sessionId: string) => ['claim-counts', sessionId] as const,
-  rateLimit: (sessionId: string) => ['rate-limit', sessionId] as const,
-  admin: (scope: string) => ['admin', scope] as const,
-};

src/lib/server/admin/resolve-credentials.ts

@@ -8,7 +8,7 @@ import {
 export interface ResolvedTtsCredentials {
   /** Provider id passed downstream to TTS generation (one of the 4 built-in IDs). */
   provider: string;
-  /** Decrypted API key from the selected admin-managed provider. */
+  /** API key for the request. Empty string when neither admin nor user supplied one. */
   apiKey: string;
   /** Base URL, or undefined to fall through to provider defaults. */
   baseUrl: string | undefined;
@@ -21,26 +21,62 @@ export interface ResolvedTtsCredentials {
 /**
  * Resolve TTS credentials for an incoming request.
  *
- * Only admin-managed shared providers can supply credentials. Built-in
- * provider ids select the preferred enabled shared provider of that type.
+ * 1. If `restrictUserApiKeys` is enabled, only admin shared providers are
+ *    used. Built-in provider ids and user-supplied key/base headers are
+ *    ignored.
+ * 2. If `providerHeader` matches an enabled admin provider slug, use its
+ *    server-stored credentials. Any `x-openai-key` / `x-openai-base-url`
+ *    headers from the client are ignored — admin keys must never round-trip
+ *    through the client.
+ * 3. Otherwise, treat `providerHeader` as a built-in provider id and use the
+ *    per-user `x-openai-key` / `x-openai-base-url` headers as today.
  *
  * Returns `null` when the request references a slug that exists but is
  * disabled — callers should reject with a 4xx.
  */
 export async function resolveTtsCredentials(opts: {
   providerHeader: string | null;
+  apiKeyHeader: string | null;
+  baseUrlHeader: string | null;
   fallbackProvider?: string;
+  restrictUserApiKeys?: boolean;
 }): Promise<ResolvedTtsCredentials | { error: 'provider_disabled' | 'provider_unknown' | 'no_shared_provider_configured'; slug: string }> {
   const requestedProvider = opts.providerHeader || opts.fallbackProvider || 'openai';
 
-  const admin = isBuiltInProviderId(requestedProvider)
-    ? await resolvePreferredEnabledAdminProvider({
-      requestedSlug: null,
-      runtimeDefaultSlug: opts.fallbackProvider || '',
-    })
-    : await getEnabledAdminProviderBySlug(requestedProvider);
+  if (opts.restrictUserApiKeys) {
+    const requestedIsBuiltIn = isBuiltInProviderId(requestedProvider);
+    const fallback = opts.fallbackProvider || '';
+    const selected = await resolvePreferredEnabledAdminProvider({
+      requestedSlug: requestedIsBuiltIn ? null : requestedProvider,
+      runtimeDefaultSlug: fallback,
+    });
+    if (!selected) {
+      return { error: 'no_shared_provider_configured', slug: requestedProvider };
+    }
+    const apiKey = await decryptedKeyFor(selected);
+    return {
+      provider: selected.providerType,
+      apiKey,
+      baseUrl: selected.baseUrl || undefined,
+      fromAdmin: true,
+      adminRecord: selected,
+    };
+  }
+
+  // Built-in provider ids are not admin slugs — short-circuit.
+  if (isBuiltInProviderId(requestedProvider)) {
+    return {
+      provider: requestedProvider,
+      apiKey: opts.apiKeyHeader || '',
+      baseUrl: opts.baseUrlHeader || undefined,
+      fromAdmin: false,
+    };
+  }
+
+  // Not a built-in id → try to look it up as an admin slug.
+  const admin = await getEnabledAdminProviderBySlug(requestedProvider);
   if (!admin) {
-    return { error: 'no_shared_provider_configured', slug: requestedProvider };
+    return { error: 'provider_unknown', slug: requestedProvider };
   }
 
   const apiKey = await decryptedKeyFor(admin);

src/lib/server/user/claim-data.ts

@@ -8,8 +8,6 @@ import {
   ttsSegmentVariants,
   userPreferences,
   userDocumentProgress,
-  userFolders,
-  userOnboarding,
 } from '@openreader/database/schema';
 import { eq, and, inArray } from 'drizzle-orm';
 import { UNCLAIMED_USER_ID } from '../storage/docstore-legacy';
@@ -117,7 +115,7 @@ export async function claimAnonymousData(
   options?: { cleanupLegacySources?: boolean },
 ) {
   if (!userId) {
-    return { documents: 0, audiobooks: 0, preferences: 0, progress: 0, documentSettings: 0, folders: 0, onboarding: 0 };
+    return { documents: 0, audiobooks: 0, preferences: 0, progress: 0, documentSettings: 0 };
   }
 
   const [claimableDocumentRows, claimableAudiobookRows] = await Promise.all([
@@ -131,16 +129,13 @@ export async function claimAnonymousData(
       .where(eq(audiobooks.userId, unclaimedUserId)) as Promise<Array<{ id: string }>>,
   ]);
 
-  const foldersClaimed = await transferUserFolders(unclaimedUserId, userId);
-  const [documentsClaimed, audiobooksClaimed, preferencesClaimed, progressClaimed, documentSettingsClaimed, onboardingClaimed] = await Promise.all([
+  const [documentsClaimed, audiobooksClaimed, preferencesClaimed, progressClaimed, documentSettingsClaimed] = await Promise.all([
     transferUserDocuments(unclaimedUserId, userId, { namespace, transferTts: true }),
     transferUserAudiobooks(unclaimedUserId, userId, namespace),
     transferUserPreferences(unclaimedUserId, userId),
     transferUserProgress(unclaimedUserId, userId),
     transferUserDocumentSettings(unclaimedUserId, userId),
-    transferUserOnboarding(unclaimedUserId, userId),
   ]);
-  await db.delete(userFolders).where(eq(userFolders.userId, unclaimedUserId));
 
   if (
     options?.cleanupLegacySources !== false
@@ -173,30 +168,9 @@ export async function claimAnonymousData(
     preferences: preferencesClaimed,
     progress: progressClaimed,
     documentSettings: documentSettingsClaimed,
-    folders: foldersClaimed,
-    onboarding: onboardingClaimed,
   };
 }
 
-export async function transferUserFolders(fromUserId: string, toUserId: string): Promise<number> {
-  if (!fromUserId || !toUserId || fromUserId === toUserId) return 0;
-  const rows = await db.select().from(userFolders).where(eq(userFolders.userId, fromUserId));
-  for (const row of rows) {
-    await db.insert(userFolders).values({ ...row, userId: toUserId }).onConflictDoNothing();
-  }
-  return rows.length;
-}
-
-export async function transferUserOnboarding(fromUserId: string, toUserId: string): Promise<number> {
-  if (!fromUserId || !toUserId || fromUserId === toUserId) return 0;
-  const rows = await db.select().from(userOnboarding).where(eq(userOnboarding.userId, fromUserId));
-  const row = rows[0];
-  if (!row) return 0;
-  await db.insert(userOnboarding).values({ ...row, userId: toUserId }).onConflictDoNothing();
-  await db.delete(userOnboarding).where(eq(userOnboarding.userId, fromUserId));
-  return 1;
-}
-
 /**
  * Transfer documents from one userId to another.
  *

src/lib/server/user/data-export.ts

@@ -61,8 +61,6 @@ export type AppendUserExportArchiveInput = {
   exportedAtMs: number;
   profileData: unknown;
   preferences: unknown | null;
-  folders?: unknown[];
-  onboarding?: unknown | null;
   readingHistory: unknown[];
   ttsUsage: unknown[];
   jobEvents: unknown[];
@@ -146,8 +144,6 @@ export async function appendUserExportArchive(input: AppendUserExportArchiveInpu
     exportedAtMs,
     profileData,
     preferences,
-    folders = [],
-    onboarding = null,
     readingHistory,
     ttsUsage,
     jobEvents,
@@ -175,8 +171,6 @@ export async function appendUserExportArchive(input: AppendUserExportArchiveInpu
   if (preferences) {
     appendJson(archive, 'preferences.json', preferences);
   }
-  appendJson(archive, 'folders.json', folders);
-  if (onboarding) appendJson(archive, 'onboarding.json', onboarding);
   appendJson(archive, 'reading_history.json', readingHistory);
   appendJson(archive, 'tts_usage.json', ttsUsage);
   appendJson(archive, 'job_events.json', jobEvents);

src/lib/server/user/preferences-normalize.ts

@@ -125,11 +125,6 @@ export function sanitizePreferencesPatch(
       case 'savedVoices':
         out[key] = sanitizeSavedVoices(value);
         break;
-      case 'documentListState':
-        if (isRecord(value)) {
-          out[key] = { ...value, folders: [] } as unknown as SyncedPreferencesPatch[typeof key];
-        }
-        break;
       default:
         break;
     }

src/lib/server/user/preferences-payload.ts

@@ -0,0 +1,52 @@
+import { normalizeVersion } from '@/lib/shared/changelog';
+
+export const USER_PREFERENCES_META_KEY = '_meta';
+export const USER_PREFERENCES_LAST_SEEN_APP_VERSION_KEY = 'lastSeenAppVersion';
+
+export type UserPreferencesMeta = Record<string, unknown> & {
+  lastSeenAppVersion?: string;
+};
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null;
+}
+
+export function deserializeUserPreferencesPayload(value: unknown): Record<string, unknown> {
+  if (typeof value === 'string') {
+    try {
+      const parsed = JSON.parse(value);
+      return isRecord(parsed) ? parsed : {};
+    } catch {
+      return {};
+    }
+  }
+  return isRecord(value) ? value : {};
+}
+
+export function extractUserPreferencesMeta(payload: unknown): UserPreferencesMeta {
+  const record = deserializeUserPreferencesPayload(payload);
+  const rawMeta = record[USER_PREFERENCES_META_KEY];
+  if (!isRecord(rawMeta)) return {};
+
+  const out: UserPreferencesMeta = { ...rawMeta };
+  const rawLastSeen = out[USER_PREFERENCES_LAST_SEEN_APP_VERSION_KEY];
+  if (typeof rawLastSeen === 'string') {
+    out[USER_PREFERENCES_LAST_SEEN_APP_VERSION_KEY] = normalizeVersion(rawLastSeen);
+  } else {
+    delete out[USER_PREFERENCES_LAST_SEEN_APP_VERSION_KEY];
+  }
+
+  return out;
+}
+
+export function withUserPreferencesMeta(
+  payload: Record<string, unknown>,
+  meta: UserPreferencesMeta,
+): Record<string, unknown> {
+  const out = { ...payload };
+  delete out[USER_PREFERENCES_META_KEY];
+  if (Object.keys(meta).length > 0) {
+    out[USER_PREFERENCES_META_KEY] = meta;
+  }
+  return out;
+}

src/lib/shared/onboarding-state.ts

@@ -0,0 +1,45 @@
+export type OnboardingStorageScope = 'local-dexie' | 'server-user-preferences' | 'hybrid';
+
+export type OnboardingStateDescriptor = {
+  /**
+   * Where this state is persisted today.
+   * - local-dexie: browser/device-local only
+   * - server-user-preferences: per-user on server
+   * - hybrid: intentionally persisted in both places
+   */
+  scope: OnboardingStorageScope;
+  /**
+   * Optional local key name when state is stored in Dexie app-config.
+   */
+  localKey?: string;
+  /**
+   * Optional server-side key when state is stored in user preferences/meta.
+   */
+  serverKey?: string;
+};
+
+/**
+ * Central registry for onboarding-related state and where each item lives.
+ * Keep this map up to date whenever onboarding persistence changes.
+ */
+export const ONBOARDING_STATE_REGISTRY = {
+  privacyAccepted: {
+    scope: 'local-dexie',
+    localKey: 'privacyAccepted',
+  },
+  firstVisitSettingsOpened: {
+    scope: 'local-dexie',
+    localKey: 'firstVisit',
+  },
+  documentsMigrationPrompted: {
+    scope: 'local-dexie',
+    localKey: 'documentsMigrationPrompted',
+  },
+  changelogLastSeenAppVersion: {
+    scope: 'server-user-preferences',
+    serverKey: '_meta.lastSeenAppVersion',
+  },
+} as const satisfies Record<string, OnboardingStateDescriptor>;
+
+export type OnboardingStateKey = keyof typeof ONBOARDING_STATE_REGISTRY;
+

src/types/config.ts

@@ -29,6 +29,8 @@ export function clampTtsSegmentMaxBlockLength(value: number | undefined | null):
 }
 
 export interface AppConfigValues {
+  apiKey: string;
+  baseUrl: string;
   viewType: ViewType;
   voiceSpeed: number;
   audioPlayerSpeed: number;
@@ -53,7 +55,10 @@ export interface AppConfigValues {
   epubWordHighlightEnabled: boolean;
   htmlHighlightEnabled: boolean;
   htmlWordHighlightEnabled: boolean;
+  firstVisit: boolean;
   documentListState: DocumentListState;
+  privacyAccepted: boolean;
+  documentsMigrationPrompted: boolean;
 }
 
 /**
@@ -70,6 +75,8 @@ export function getAppConfigDefaults(): AppConfigValues {
   // provider id (the old 'custom-openai') into every user's config, since that
   // value isn't actually selectable in shared-provider mode.
   return {
+    apiKey: '',
+    baseUrl: '',
     viewType: 'single',
     voiceSpeed: 1,
     audioPlayerSpeed: 1,
@@ -94,6 +101,7 @@ export function getAppConfigDefaults(): AppConfigValues {
     epubWordHighlightEnabled: true,
     htmlHighlightEnabled: true,
     htmlWordHighlightEnabled: true,
+    firstVisit: false,
     documentListState: {
       sortBy: 'name',
       sortDirection: 'asc',
@@ -102,6 +110,8 @@ export function getAppConfigDefaults(): AppConfigValues {
       showHint: true,
       viewMode: 'grid',
     },
+    privacyAccepted: false,
+    documentsMigrationPrompted: false,
   };
 }
 

src/types/documents.ts

@@ -6,7 +6,6 @@ export interface BaseDocument {
   size: number;
   lastModified: number;
   recentlyOpenedAt?: number;
-  contentVersion?: string;
   type: DocumentType;
   scope?: 'user';
   folderId?: string;

src/types/user-state.ts

@@ -25,7 +25,6 @@ export const SYNCED_PREFERENCE_KEYS = [
   'epubWordHighlightEnabled',
   'htmlHighlightEnabled',
   'htmlWordHighlightEnabled',
-  'documentListState',
 ] as const;
 
 export type SyncedPreferenceKey = (typeof SYNCED_PREFERENCE_KEYS)[number];

tests/folders.spec.ts

@@ -84,7 +84,7 @@ test.describe('Document folders and hint persistence', () => {
     // Hint should disappear
     await expect(hint).toHaveCount(0);
 
-    // Ensure the dismissal has been persisted to server preferences before reloading
+    // Ensure the dismissal has been persisted to IndexedDB before reloading
     await waitForDocumentListHintPersist(page, false);
 
     // Reload and ensure it remains dismissed

tests/helpers.ts

@@ -533,14 +533,27 @@ export async function triggerViewportResize(page: Page, width: number, height: n
   await page.setViewportSize({ width, height });
 }
 
-// Wait for DocumentListState.showHint to persist in server preferences.
+// Wait for DocumentListState.showHint to persist in IndexedDB 'app-config' store
 export async function waitForDocumentListHintPersist(page: Page, expected: boolean) {
   await page.waitForFunction(async (exp) => {
     try {
-      const response = await fetch('/api/user/state/preferences', { cache: 'no-store' });
-      if (!response.ok) return false;
-      const item = await response.json() as { preferences?: { documentListState?: unknown } };
-      const state = item.preferences?.documentListState;
+      const openDb = () => new Promise<IDBDatabase>((resolve, reject) => {
+        const req = indexedDB.open('openreader-db');
+        req.onsuccess = () => resolve(req.result);
+        req.onerror = () => reject(req.error);
+      });
+      const db = await openDb();
+      const readConfig = () => new Promise<unknown>((resolve, reject) => {
+        const tx = db.transaction(['app-config'], 'readonly');
+        const store = tx.objectStore('app-config');
+        const getReq = store.get('singleton');
+        getReq.onsuccess = () => resolve(getReq.result);
+        getReq.onerror = () => reject(getReq.error);
+      });
+      const item = await readConfig();
+      db.close();
+      if (!item || typeof item !== 'object') return false;
+      const state = (item as { documentListState?: unknown }).documentListState;
       if (!state || typeof state !== 'object') return false;
       const showHint = (state as { showHint?: unknown }).showHint;
       return typeof showHint === 'boolean' && showHint === exp;

tests/unit/blob-cache.vitest.spec.ts

@@ -1,74 +0,0 @@
-import { afterEach, describe, expect, test, vi } from 'vitest';
-import {
-  audioBlobCacheKey,
-  documentBlobCacheKey,
-  getCachedBlob,
-  previewBlobCacheKey,
-} from '../../src/lib/client/cache/blob-cache';
-
-afterEach(() => {
-  vi.unstubAllGlobals();
-});
-
-describe('blob cache stable keys', () => {
-  test('builds versioned synthetic keys', () => {
-    expect(documentBlobCacheKey('doc/id', 'v1')).toBe('/openreader-cache/documents/doc%2Fid/v1');
-    expect(previewBlobCacheKey('doc', 'etag/1')).toBe('/openreader-cache/previews/doc/etag%2F1');
-    expect(audioBlobCacheKey('audio/key', 2)).toBe('/openreader-cache/audio/audio%2Fkey/2');
-  });
-
-  test('returns a cache hit without fetching', async () => {
-    const cached = new Response('cached');
-    const match = vi.fn().mockResolvedValue(cached);
-    vi.stubGlobal('window', {});
-    vi.stubGlobal('caches', { open: vi.fn().mockResolvedValue({ match, put: vi.fn() }) });
-    const fetchSource = vi.fn();
-
-    expect(await (await getCachedBlob('/openreader-cache/documents/doc/v1', fetchSource)).text()).toBe('cached');
-    expect(fetchSource).not.toHaveBeenCalled();
-  });
-
-  test('fetches and caches a successful full response on a miss', async () => {
-    const put = vi.fn().mockResolvedValue(undefined);
-    vi.stubGlobal('window', {});
-    vi.stubGlobal('caches', {
-      open: vi.fn().mockResolvedValue({ match: vi.fn().mockResolvedValue(undefined), put }),
-    });
-
-    const response = await getCachedBlob('/openreader-cache/documents/doc/v2', async () => new Response('network'));
-    expect(await response.text()).toBe('network');
-    expect(put).toHaveBeenCalledOnce();
-  });
-
-  test('treats missing Cache Storage and cache write failures as non-fatal', async () => {
-    vi.stubGlobal('window', {});
-    vi.stubGlobal('caches', {
-      open: vi.fn()
-        .mockRejectedValueOnce(new Error('unavailable'))
-        .mockResolvedValueOnce({
-          match: vi.fn().mockResolvedValue(undefined),
-          put: vi.fn().mockRejectedValue(new Error('quota')),
-        }),
-    });
-
-    expect(await (await getCachedBlob('/openreader-cache/documents/doc/v3', async () => new Response('first'))).text()).toBe('first');
-    expect(await (await getCachedBlob('/openreader-cache/documents/doc/v4', async () => new Response('second'))).text()).toBe('second');
-  });
-
-  test('does not cache partial responses and throws for failed fetches', async () => {
-    const put = vi.fn();
-    vi.stubGlobal('window', {});
-    vi.stubGlobal('caches', {
-      open: vi.fn().mockResolvedValue({ match: vi.fn().mockResolvedValue(undefined), put }),
-    });
-
-    const partial = await getCachedBlob(
-      '/openreader-cache/audio/key/v1',
-      async () => new Response('partial', { status: 206, headers: { 'Content-Range': 'bytes 0-6/20' } }),
-    );
-    expect(partial.status).toBe(206);
-    expect(put).not.toHaveBeenCalled();
-    await expect(getCachedBlob('/openreader-cache/audio/key/v2', async () => new Response(null, { status: 404 })))
-      .rejects.toThrow('Blob fetch failed: 404');
-  });
-});

tests/unit/document-cache.vitest.spec.ts

@@ -0,0 +1,114 @@
+import { describe, expect, test } from 'vitest';
+import type { BaseDocument, EPUBDocument, HTMLDocument, PDFDocument } from '../../src/types/documents';
+import { ensureCachedDocumentCore } from '../../src/lib/client/cache/documents';
+import { makeBaseDocument } from './support/document-fixtures';
+
+describe('document-cache-core', () => {
+  test('returns cached PDF without downloading', async () => {
+    const meta: BaseDocument = makeBaseDocument({
+      id: 'pdf1',
+      name: 'a.pdf',
+      size: 10,
+      lastModified: 1_700_000_000_001,
+      type: 'pdf',
+    });
+
+    let downloads = 0;
+    const cached: PDFDocument = { ...meta, type: 'pdf', data: new ArrayBuffer(1) };
+
+    const result = await ensureCachedDocumentCore(meta, {
+      get: async () => cached,
+      putPdf: async () => { throw new Error('should not put'); },
+      putEpub: async () => { throw new Error('should not put'); },
+      putHtml: async () => { throw new Error('should not put'); },
+      download: async () => {
+        downloads++;
+        return new ArrayBuffer(0);
+      },
+      decodeText: () => '',
+    });
+
+    expect(downloads).toBe(0);
+    expect(result.type).toBe('pdf');
+  });
+
+  test('downloads and stores on cache miss (EPUB)', async () => {
+    const meta: BaseDocument = makeBaseDocument({
+      id: 'epub1',
+      name: 'b.epub',
+      size: 10,
+      lastModified: 1_700_000_000_002,
+      type: 'epub',
+    });
+
+    const store = new Map<string, PDFDocument | EPUBDocument | HTMLDocument>();
+    let downloads = 0;
+
+    const result = await ensureCachedDocumentCore(meta, {
+      get: async (m) => store.get(m.id) ?? null,
+      putPdf: async () => { /* unused */ },
+      putEpub: async (m, data) => {
+        store.set(m.id, { ...m, type: 'epub', data } as EPUBDocument);
+      },
+      putHtml: async () => { /* unused */ },
+      download: async () => {
+        downloads++;
+        return new Uint8Array([1, 2, 3]).buffer;
+      },
+      decodeText: () => '',
+    });
+
+    expect(downloads).toBe(1);
+    expect(result.type).toBe('epub');
+    expect((result as EPUBDocument).data.byteLength).toBe(3);
+  });
+
+  test('downloads, decodes, and stores HTML on cache miss', async () => {
+    const meta: BaseDocument = makeBaseDocument({
+      id: 'html1',
+      name: 'c.txt',
+      size: 5,
+      lastModified: 1_700_000_000_003,
+      type: 'html',
+    });
+
+    const store = new Map<string, PDFDocument | EPUBDocument | HTMLDocument>();
+    let decodedCalls = 0;
+
+    const result = await ensureCachedDocumentCore(meta, {
+      get: async (m) => store.get(m.id) ?? null,
+      putPdf: async () => { /* unused */ },
+      putEpub: async () => { /* unused */ },
+      putHtml: async (m, data) => {
+        store.set(m.id, { ...m, type: 'html', data } as HTMLDocument);
+      },
+      download: async () => new TextEncoder().encode('hello').buffer,
+      decodeText: (buf) => {
+        decodedCalls++;
+        return new TextDecoder().decode(new Uint8Array(buf));
+      },
+    });
+
+    expect(decodedCalls).toBe(1);
+    expect(result.type).toBe('html');
+    expect((result as HTMLDocument).data).toBe('hello');
+  });
+
+  test('throws deterministic cache error when download succeeds but backend misses persisted PDF', async () => {
+    const meta = makeBaseDocument({
+      id: 'pdf-cache-miss',
+      type: 'pdf',
+    });
+
+    await expect(
+      ensureCachedDocumentCore(meta, {
+        get: async () => null,
+        putPdf: async () => { /* simulate write path without persisted row */ },
+        putEpub: async () => { /* unused */ },
+        putHtml: async () => { /* unused */ },
+        download: async () => new Uint8Array([1, 2, 3]).buffer,
+        decodeText: () => '',
+      }),
+    ).rejects.toThrow('Failed to cache PDF');
+  });
+});

tests/unit/epub-location-controller.vitest.spec.ts

@@ -4,7 +4,7 @@ import {
   isDirectionalEpubLocation,
   shouldNavigateToDifferentCfi,
   shouldPersistEpubLocation,
-} from '../../src/lib/client/epub/location-controller';
+} from '../../src/hooks/epub/useEPUBLocationController';
 
 describe('EPUB location controller helpers', () => {
   test('detects directional locations', () => {

tests/unit/onboarding-flow.vitest.spec.ts

@@ -9,6 +9,7 @@ describe('onboarding flow resolver', () => {
       privacyAccepted: false,
       claimEligible: true,
       claimHasData: true,
+      migrationRequired: true,
       changelogPending: true,
     });
 
@@ -21,18 +22,33 @@ describe('onboarding flow resolver', () => {
       privacyAccepted: true,
       claimEligible: true,
       claimHasData: true,
+      migrationRequired: true,
       changelogPending: true,
     });
 
     expect(step).toBe('claim');
   });
 
+  test('resolves migration when no claim is needed', () => {
+    const step = resolveNextOnboardingStep({
+      privacyRequired: true,
+      privacyAccepted: true,
+      claimEligible: true,
+      claimHasData: false,
+      migrationRequired: true,
+      changelogPending: true,
+    });
+
+    expect(step).toBe('migration');
+  });
+
   test('resolves changelog when prior steps are clear', () => {
     const step = resolveNextOnboardingStep({
       privacyRequired: true,
       privacyAccepted: true,
       claimEligible: true,
       claimHasData: false,
+      migrationRequired: false,
       changelogPending: true,
     });
 
@@ -45,6 +61,7 @@ describe('onboarding flow resolver', () => {
       privacyAccepted: true,
       claimEligible: true,
       claimHasData: false,
+      migrationRequired: false,
       changelogPending: false,
     });
     const minimalStep = resolveNextOnboardingStep({
@@ -52,6 +69,7 @@ describe('onboarding flow resolver', () => {
       privacyAccepted: false,
       claimEligible: false,
       claimHasData: false,
+      migrationRequired: false,
       changelogPending: false,
     });
 

tests/unit/onboarding-state.vitest.spec.ts

@@ -0,0 +1,19 @@
+import { describe, expect, test } from 'vitest';
+import { ONBOARDING_STATE_REGISTRY } from '../../src/lib/shared/onboarding-state';
+import { SYNCED_PREFERENCE_KEYS } from '../../src/types/user-state';
+
+describe('onboarding state storage scopes', () => {
+  test('keeps local onboarding flags out of synced server preferences', () => {
+    expect(ONBOARDING_STATE_REGISTRY.privacyAccepted.scope).toBe('local-dexie');
+    expect(ONBOARDING_STATE_REGISTRY.firstVisitSettingsOpened.scope).toBe('local-dexie');
+    expect(ONBOARDING_STATE_REGISTRY.documentsMigrationPrompted.scope).toBe('local-dexie');
+    expect(ONBOARDING_STATE_REGISTRY.changelogLastSeenAppVersion.scope).toBe('server-user-preferences');
+
+    const synced = new Set<string>(SYNCED_PREFERENCE_KEYS);
+
+    expect(synced.has(ONBOARDING_STATE_REGISTRY.privacyAccepted.localKey!)).toBe(false);
+    expect(synced.has(ONBOARDING_STATE_REGISTRY.firstVisitSettingsOpened.localKey!)).toBe(false);
+    expect(synced.has(ONBOARDING_STATE_REGISTRY.documentsMigrationPrompted.localKey!)).toBe(false);
+  });
+});
+

tests/unit/query-keys.vitest.spec.ts

@@ -1,19 +0,0 @@
-import { describe, expect, test } from 'vitest';
-import { queryKeys } from '../../src/lib/client/query-keys';
-
-describe('query keys', () => {
-  test('isolates server state by session and document', () => {
-    expect(queryKeys.documents('user-a')).not.toEqual(queryKeys.documents('user-b'));
-    expect(queryKeys.progress('user-a', 'doc-a')).not.toEqual(queryKeys.progress('user-a', 'doc-b'));
-    expect(queryKeys.documentSettings('user-a', 'doc-a')).not.toEqual(queryKeys.documentSettings('user-b', 'doc-a'));
-  });
-
-  test('defines centralized keys for migrated server-state domains', () => {
-    expect(queryKeys.preferences('user')).toEqual(['preferences', 'user']);
-    expect(queryKeys.onboarding('user')).toEqual(['onboarding', 'user']);
-    expect(queryKeys.folders('user')).toEqual(['folders', 'user']);
-    expect(queryKeys.audiobook('user', 'book')).toEqual(['audiobook', 'user', 'book']);
-    expect(queryKeys.ttsManifest('user', 'doc')).toEqual(['tts-manifest', 'user', 'doc']);
-    expect(queryKeys.parsedDocument('user', 'doc')).toEqual(['parsed-document', 'user', 'doc']);
-  });
-});

tests/unit/transfer-user-documents.vitest.spec.ts

@@ -25,8 +25,6 @@ describe('transferUserDocuments', () => {
         size INTEGER NOT NULL,
         last_modified INTEGER NOT NULL,
         file_path TEXT NOT NULL,
-        folder_id TEXT,
-        recently_opened_at INTEGER,
         parse_state TEXT,
         parsed_json_key TEXT,
         created_at INTEGER,
@@ -151,8 +149,6 @@ describe('transferUserDocuments', () => {
         size INTEGER NOT NULL,
         last_modified INTEGER NOT NULL,
         file_path TEXT NOT NULL,
-        folder_id TEXT,
-        recently_opened_at INTEGER,
         parse_state TEXT,
         parsed_json_key TEXT,
         created_at INTEGER,

tests/unit/tts-provider-catalog.vitest.spec.ts

@@ -533,6 +533,7 @@ describe('config helpers', () => {
   test('builds synced preference patches and honors non-default filtering', () => {
     expect(buildSyncedPreferencePatch({
       voiceSpeed: 1.2,
+      baseUrl: 'http://localhost',
       ttsModel: 'kokoro',
     })).toEqual({
       voiceSpeed: 1.2,

tests/unit/user-preferences-sync.vitest.spec.ts

@@ -0,0 +1,81 @@
+import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
+
+import {
+  cancelPendingPreferenceSync,
+  flushUserPreferencesSync,
+  scheduleUserPreferencesSync,
+} from '../../src/lib/client/api/user-state';
+
+type FetchMock = ReturnType<typeof vi.fn> & { calls: Array<{ url: string; init?: RequestInit }> };
+
+function installFetchMock(responder: () => Response): FetchMock {
+  const mock = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
+    mock.calls.push({ url: String(input), init });
+    return responder();
+  }) as unknown as FetchMock;
+  mock.calls = [];
+  global.fetch = mock as unknown as typeof fetch;
+  return mock;
+}
+
+function okResponse(): Response {
+  return new Response(
+    JSON.stringify({ preferences: {}, clientUpdatedAtMs: Date.now(), applied: true }),
+    { status: 200, headers: { 'Content-Type': 'application/json' } },
+  );
+}
+
+describe('flushUserPreferencesSync', () => {
+  const originalFetch = global.fetch;
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+    cancelPendingPreferenceSync();
+  });
+
+  afterEach(() => {
+    cancelPendingPreferenceSync();
+    vi.useRealTimers();
+    global.fetch = originalFetch;
+  });
+
+  test('sends a pending debounced patch immediately instead of waiting for the timer', async () => {
+    const fetchMock = installFetchMock(okResponse);
+
+    scheduleUserPreferencesSync({ providerRef: 'shared-b', providerType: 'openai' }, 'user-1');
+
+    // Nothing should have fired yet — it's still debounced.
+    expect(fetchMock.calls).toHaveLength(0);
+
+    await flushUserPreferencesSync();
+
+    expect(fetchMock.calls).toHaveLength(1);
+    const { url, init } = fetchMock.calls[0];
+    expect(url).toContain('/api/user/state/preferences');
+    expect(init?.method).toBe('PUT');
+    const body = JSON.parse(String(init?.body));
+    expect(body.patch.providerRef).toBe('shared-b');
+    expect(body.patch.providerType).toBe('openai');
+
+    // The debounce timer must not also fire a duplicate request afterwards.
+    await vi.runAllTimersAsync();
+    expect(fetchMock.calls).toHaveLength(1);
+  });
+
+  test('is a no-op when there is no pending patch', async () => {
+    const fetchMock = installFetchMock(okResponse);
+    await flushUserPreferencesSync();
+    expect(fetchMock.calls).toHaveLength(0);
+  });
+
+  test('rejects when the server write fails so callers can surface the error', async () => {
+    installFetchMock(() => new Response(JSON.stringify({ error: 'boom' }), {
+      status: 500,
+      headers: { 'Content-Type': 'application/json' },
+    }));
+
+    scheduleUserPreferencesSync({ providerRef: 'shared-b' }, 'user-1');
+
+    await expect(flushUserPreferencesSync()).rejects.toThrow();
+  });
+});

tests/upload.spec.ts

@@ -1,9 +1,14 @@
 import { test, expect } from '@playwright/test';
 import { uploadFile, uploadAndDisplay, setupTest, expectDocumentListed, uploadFiles, ensureDocumentsListed, clickDocumentLink, expectViewerForFile } from './helpers';
 
+interface HtmlDocumentRow {
+  id?: string;
+  data?: string;
+}
+
 type HashCheckResult =
   | { ok: true; storedId: string; computedId: string }
-  | { ok: false; reason: 'Missing stored html document' | 'Hash mismatch' | 'Content fetch failed'; storedId?: string; computedId?: string };
+  | { ok: false; reason: 'Missing stored html document' | 'Hash mismatch'; storedId?: string; computedId?: string };
 
 test.describe('Document Upload Tests', () => {
   test.beforeEach(async ({ page }, testInfo) => {
@@ -53,24 +58,38 @@ test.describe('Document Upload Tests', () => {
     await expectDocumentListed(page, 'sample.txt');
 
     const result = await page.evaluate<HashCheckResult>(async () => {
-      const listRes = await fetch('/api/documents', { cache: 'no-store' });
-      const docs = listRes.ok
-        ? ((await listRes.json()) as { documents?: Array<{ id: string; name: string }> }).documents ?? []
-        : [];
-      const doc = docs.find((item) => item.name === 'sample.txt');
-      if (!doc?.id) return { ok: false, reason: 'Missing stored html document' as const };
+      const idb = await new Promise<IDBDatabase>((resolve, reject) => {
+        const request = indexedDB.open('openreader-db');
+        request.onerror = () => reject(request.error);
+        request.onsuccess = () => resolve(request.result);
+      });
 
-      const contentRes = await fetch(`/api/documents/blob/get/fallback?id=${encodeURIComponent(doc.id)}`, { cache: 'no-store' });
-      if (!contentRes.ok) return { ok: false, reason: 'Content fetch failed' as const, storedId: doc.id };
-      const digest = await crypto.subtle.digest('SHA-256', await contentRes.arrayBuffer());
-      const computedId = Array.from(new Uint8Array(digest))
-        .map((b) => b.toString(16).padStart(2, '0'))
-        .join('');
+      try {
+        const docs = await new Promise<HtmlDocumentRow[]>((resolve, reject) => {
+          const tx = idb.transaction('html-documents', 'readonly');
+          const store = tx.objectStore('html-documents');
+          const request = store.getAll();
+          request.onerror = () => reject(request.error);
+          request.onsuccess = () => resolve(request.result as HtmlDocumentRow[]);
+        });
 
-      if (computedId === doc.id) {
-        return { ok: true as const, storedId: doc.id, computedId };
+        if (!docs[0]?.data || !docs[0]?.id) {
+          return { ok: false, reason: 'Missing stored html document' as const };
+        }
+
+        const bytes = new TextEncoder().encode(String(docs[0].data));
+        const digest = await crypto.subtle.digest('SHA-256', bytes);
+        const computedId = Array.from(new Uint8Array(digest))
+          .map((b) => b.toString(16).padStart(2, '0'))
+          .join('');
+
+        if (computedId === docs[0].id) {
+          return { ok: true as const, storedId: docs[0].id as string, computedId };
+        }
+        return { ok: false as const, reason: 'Hash mismatch', storedId: docs[0].id as string, computedId };
+      } finally {
+        idb.close();
       }
-      return { ok: false as const, reason: 'Hash mismatch', storedId: doc.id, computedId };
     });
 
     const detail = result.ok