feat(stats): add Hide Kana filter and fix vocabulary exclusion matching

- Remove overlay mining image toast; OSD card notifications no longer flash a frame screenshot
- Add Hide Kana toggle to frequency rank table to filter kana-only headwords
- Fix vocab exclusions to deduplicate and match token variants (e.g. ない / 無い) under one exclusion entry
- Skip cover image fetching when the overview tab is inactive

src/main.ts

@@ -3266,10 +3266,6 @@ function broadcastToOverlayWindows(channel: string, ...args: unknown[]): void {
   overlayManager.broadcastToOverlayWindows(channel, ...args);
 }
 
-function broadcastMiningImageToOverlay(image: string): void {
-  broadcastToOverlayWindows(IPC_CHANNELS.event.miningImage, { image });
-}
-
 const buildBroadcastRuntimeOptionsChangedMainDepsHandler =
   createBuildBroadcastRuntimeOptionsChangedMainDepsHandler({
     broadcastRuntimeOptionsChangedRuntime,
@@ -5815,7 +5811,6 @@ function initializeOverlayRuntime(): void {
     refreshCurrentSubtitleAfterKnownWordUpdate,
   );
   appState.ankiIntegration?.setSubtitleMiningContextConsumer(consumePendingSubtitleMiningContext);
-  appState.ankiIntegration?.setMiningImageOverlayCallback(broadcastMiningImageToOverlay);
   syncOverlayMpvSubtitleSuppression();
 }
 
@@ -6901,7 +6896,6 @@ const { registerIpcRuntimeHandlers } = composeIpcRuntimeHandlers({
         appState.ankiIntegration?.setSubtitleMiningContextConsumer(
           consumePendingSubtitleMiningContext,
         );
-        appState.ankiIntegration?.setMiningImageOverlayCallback(broadcastMiningImageToOverlay);
       },
       getKnownWordCacheStatePath: () => path.join(USER_DATA_PATH, 'known-words-cache.json'),
       showDesktopNotification,