refactor(webui): theme shared import controls

- add a shared switch primitive for theme-aware toggle styling\n- keep import-page buttons leaning on shared variants instead of local color rules\n- simplify the singles and auto-import controls around the shared form layer

webui/src/components/form/form.module.css

@@ -183,6 +183,62 @@
   transform: translateY(-0.5px) scaleX(1.18);
 }
 
+.switch {
+  position: relative;
+  display: inline-flex;
+  align-items: center;
+  width: 44px;
+  height: 24px;
+  flex-shrink: 0;
+  box-sizing: border-box;
+  margin: 0;
+  padding: 0 3px;
+  border: 1px solid rgba(255, 255, 255, 0.16);
+  border-radius: 999px;
+  background:
+    linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.04)),
+    rgba(255, 255, 255, 0.06);
+  cursor: pointer;
+  transition:
+    border-color 0.18s ease,
+    background 0.18s ease,
+    box-shadow 0.18s ease,
+    transform 0.18s ease;
+  color-scheme: dark;
+}
+
+.switch[data-checked] {
+  border-color: rgba(var(--accent-light-rgb), 0.55);
+  background:
+    linear-gradient(180deg, rgba(var(--accent-light-rgb), 0.55), rgba(var(--accent-rgb), 0.8)),
+    rgba(var(--accent-rgb), 0.45);
+}
+
+.switch[data-focused] {
+  outline: none;
+  box-shadow: 0 0 0 3px rgba(var(--accent-light-rgb), 0.14);
+}
+
+.switch[data-disabled] {
+  opacity: 0.55;
+  cursor: not-allowed;
+}
+
+.switchThumb {
+  display: block;
+  width: 18px;
+  height: 18px;
+  border-radius: 50%;
+  background: #fff;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25);
+  transform: translateX(0);
+  transition: transform 0.18s ease;
+}
+
+.switch[data-checked] .switchThumb {
+  transform: translateX(20px);
+}
+
 .rangeRoot {
   display: inline-flex;
   flex: 0 0 160px;

webui/src/components/form/form.test.tsx

@@ -14,6 +14,7 @@ import {
   OptionCardGroup,
   RangeInput,
   Select,
+  Switch,
   TextArea,
   TextInput,
 } from './form';
@@ -25,6 +26,7 @@ function FormDemo() {
   const [priority, setPriority] = useState<'low' | 'normal' | 'high'>('normal');
   const [status, setStatus] = useState('open');
   const [archive, setArchive] = useState(false);
+  const [enabled, setEnabled] = useState(true);
   const [confidence, setConfidence] = useState(90);
 
   return (
@@ -98,6 +100,10 @@ function FormDemo() {
         <Checkbox checked={archive} onCheckedChange={setArchive} />
       </FormField>
 
+      <FormField label="Enabled" helperText="Shared switch primitive">
+        <Switch checked={enabled} onCheckedChange={setEnabled} />
+      </FormField>
+
       <FormField label="Confidence" helperText="Shared range primitive">
         <RangeInput
           label="Confidence"
@@ -137,6 +143,11 @@ describe('form primitives', () => {
     fireEvent.click(archiveCheckbox);
     expect(archiveCheckbox).toBeChecked();
 
+    const enabledSwitch = screen.getByRole('switch', { name: 'Enabled' });
+    expect(enabledSwitch).toBeChecked();
+    fireEvent.click(enabledSwitch);
+    expect(enabledSwitch).not.toBeChecked();
+
     const confidenceSlider = screen.getByLabelText('Confidence', { selector: 'input' });
     expect(confidenceSlider).toHaveValue('90');
     fireEvent.change(confidenceSlider, { target: { value: '75' } });

webui/src/components/form/form.tsx

@@ -3,6 +3,7 @@ import { Checkbox as BaseCheckbox } from '@base-ui/react/checkbox';
 import { Field } from '@base-ui/react/field';
 import { Input as BaseInput } from '@base-ui/react/input';
 import { Slider } from '@base-ui/react/slider';
+import { Switch as BaseSwitch } from '@base-ui/react/switch';
 import { Toggle as BaseToggle } from '@base-ui/react/toggle';
 import clsx from 'clsx';
 import {
@@ -106,6 +107,23 @@ export const Checkbox = forwardRef<HTMLElement, CheckboxProps>(function Checkbox
   );
 });
 
+type BaseSwitchProps = ComponentPropsWithoutRef<typeof BaseSwitch.Root>;
+
+export type SwitchProps = Omit<BaseSwitchProps, 'className' | 'children'> & {
+  className?: string;
+};
+
+export const Switch = forwardRef<HTMLElement, SwitchProps>(function Switch(
+  { className, ...props },
+  ref,
+) {
+  return (
+    <BaseSwitch.Root ref={ref} className={clsx(styles.switch, className)} {...props}>
+      <BaseSwitch.Thumb className={styles.switchThumb} />
+    </BaseSwitch.Root>
+  );
+});
+
 export interface RangeInputProps {
   className?: string;
   disabled?: boolean;

webui/src/routes/import/-ui/auto-import-tab.tsx

@@ -1,7 +1,7 @@
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import { useEffect, useState } from 'react';
 
-import { Button, RangeInput, Select } from '@/components/form/form';
+import { Button, RangeInput, Select, Switch } from '@/components/form/form';
 
 import type {
   ImportAutoFilter,
@@ -155,17 +155,16 @@ export function AutoImportPanel({
     <>
       <div className={styles.autoImportControls}>
         <div className={styles.autoImportToggleRow}>
-          <label className={styles.autoImportToggleLabel}>
-            <input
-              type="checkbox"
-              id="auto-import-enabled"
+          <div className={styles.autoImportToggleLabel}>
+            <Switch
               checked={Boolean(statusQuery.data?.running)}
               disabled={toggleMutation.isPending}
-              onChange={(event) => toggleMutation.mutate(event.target.checked)}
+              aria-labelledby="auto-import-toggle-label"
+              id="auto-import-enabled"
+              onCheckedChange={(checked) => toggleMutation.mutate(checked)}
             />
-            <span className={styles.autoImportToggleSlider} />
-            <span>Auto-Import</span>
-          </label>
+            <span id="auto-import-toggle-label">Auto-Import</span>
+          </div>
           <span
             className={`${styles.autoImportStatus} ${styles[statusClassName]}`}
             id="auto-import-status-text"

webui/src/routes/import/-ui/import-page.module.css

@@ -1024,46 +1024,11 @@
   display: flex;
   align-items: center;
   gap: 8px;
-  cursor: pointer;
   font-size: 13px;
   font-weight: 600;
   color: rgba(255, 255, 255, 0.7);
 }
 
-.autoImportToggleLabel input {
-  display: none;
-}
-
-.autoImportToggleSlider {
-  position: relative;
-  width: 44px;
-  height: 24px;
-  background: rgba(255, 255, 255, 0.12);
-  border-radius: 12px;
-  transition: background 0.2s ease;
-  display: inline-block;
-}
-
-.autoImportToggleSlider::after {
-  content: '';
-  position: absolute;
-  top: 3px;
-  left: 3px;
-  width: 18px;
-  height: 18px;
-  background: #fff;
-  border-radius: 50%;
-  transition: transform 0.2s ease;
-}
-
-.autoImportToggleLabel input:checked + .autoImportToggleSlider {
-  background: var(--accent-color, #6366f1);
-}
-
-.autoImportToggleLabel input:checked + .autoImportToggleSlider::after {
-  transform: translateX(20px);
-}
-
 .autoImportStatus {
   font-size: 12px;
   font-weight: 500;
@@ -1102,7 +1067,7 @@
   display: inline-block;
   flex: 0 0 5ch;
   width: 5ch;
-  text-align: right;
+  text-align: center;
   font-variant-numeric: tabular-nums;
 }
 .autoImportEmpty {

webui/src/routes/import/-ui/singles-import-tab.tsx

@@ -169,6 +169,7 @@ export function SinglesImportPanel({
 }) {
   const selectedCount = files.filter((file) => selected.has(getStagingFileKey(file))).length;
   const allSelected = files.length > 0 && selectedCount === files.length;
+  const processVariant = selectedCount > 0 ? 'primary' : 'default';
 
   return (
     <>
@@ -181,7 +182,7 @@ export function SinglesImportPanel({
           </Button>
           <Button
             type="button"
-            variant="primary"
+            variant={processVariant}
             id="import-page-singles-process-btn"
             disabled={selectedCount === 0}
             onClick={onProcessSingles}