Migrates scattered configuration items and last document locations
from the legacy `config` table to new, dedicated Dexie stores.
- Introduces a singleton `app-config` table (`AppConfigRow`) to standardize
and structure all application settings in a single object.
- Creates a `last-locations` table for efficient storage of document read positions.
- Updates `ConfigContext` to utilize `dexie-react-hooks`' `useLiveQuery`
for reactive and simplified state management.
- Implements a database upgrade path (from DB_VERSION 4 to 5) to migrate
all existing user settings seamlessly.
- Simplifies config access and updates with new `getAppConfig` and `updateAppConfig`
utility functions.
- Removes the deprecated `config` table after successful migration.
- Updates consumers like `SettingsModal` and test helpers to align with
the new config structure.
- Reduce Playwright worker allocation from 75% to 50% for better resource management
- Disable parallel test execution temporarily to isolate flaky test behavior
- Enhance audio utility to fail fast on user cancellation, preventing unnecessary retries
- Consolidate test-specific utilities within individual test suites for better isolation
- Introduce export functionality test coverage with new export.spec.ts suite
introduce configurable smart sentence splitting with persisted state,
UI toggle, and EPUB/PDF contexts that send continuation metadata.
enhance TTS pipeline to merge cross-page sentences, manage carryover,
and trigger visual page changes during playback for smoother narration.
update README with kokoro quick-start guidance, remove the legacy
issues mapping doc, and add deterministic TTS mocks plus sample audio
for Playwright tests.
