feat(notifications): add overlay notifications with position config

- Add Catppuccin Macchiato overlay notification stack with 3s transient timeout
- Add `notifications.overlayPosition` config (top-left | top | top-right)
- Route startup tokenization and subtitle annotation status through configured surfaces
- Deduplicate rapid subtitle mode toggle notifications
- Change `both` to mean overlay + system; add `osd-system` as legacy alias for old behavior
- Keep `osd`/`osd-system` as config-file-only legacy values; Settings UI offers overlay/system/both/none

src/config/settings/registry.ts

@@ -151,6 +151,7 @@ const SECTION_ORDER = new Map<string, number>(
     'Startup warmups',
     'Logging',
     'Updates',
+    'Notifications',
     'Immersion tracking',
   ].map((section, index) => [section, index]),
 );
@@ -411,6 +412,9 @@ function categoryAndSection(path: string): { category: ConfigSettingsCategory; s
   ) {
     return { category: 'behavior', section: 'Playback Behavior' };
   }
+  if (path.startsWith('notifications.')) {
+    return { category: 'behavior', section: 'Notifications' };
+  }
   if (path === 'mpv.aniskipButtonKey') {
     return { category: 'input', section: 'Overlay Shortcuts' };
   }
@@ -478,6 +482,7 @@ function topSection(path: string): string {
     mpv: 'mpv Playback',
     stats: 'Stats dashboard',
     startupWarmups: 'Startup warmups',
+    notifications: 'Notifications',
     subsync: 'Subtitle Sync',
     texthooker: 'Texthooker',
     updates: 'Updates',
@@ -686,6 +691,7 @@ function restartBehaviorForPath(path: string): ConfigSettingsRestartBehavior {
     path === 'logging.level' ||
     path === 'logging.rotation' ||
     pathStartsWith(path, 'logging.files') ||
+    pathStartsWith(path, 'notifications') ||
     path === 'youtube.primarySubLanguages' ||
     pathStartsWith(path, 'jimaku') ||
     pathStartsWith(path, 'subsync')
@@ -709,7 +715,9 @@ function fieldForLeaf(leaf: Leaf): ConfigSettingsField {
     ...(subsectionForPath(leaf.path) ? { subsection: subsectionForPath(leaf.path) } : {}),
     control: controlForPath(leaf.path, leaf.value),
     defaultValue: leaf.value,
-    ...(option?.enumValues ? { enumValues: option.enumValues } : {}),
+    ...(option?.settingsEnumValues || option?.enumValues
+      ? { enumValues: option.settingsEnumValues ?? option.enumValues }
+      : {}),
     restartBehavior: restartBehaviorForPath(leaf.path),
     advanced:
       leaf.path.startsWith('controller.') ||