fix(anki): prevent media timing review hangs and invalid ranges

- Reject stale or invalid timing actions
- Fall back to original timing when the renderer stops responding

src/renderer/handlers/keyboard.test.ts

@@ -494,6 +494,7 @@ function createKeyboardHandlerHarness() {
     handleKikuKeydown: () => false,
     handleJimakuKeydown: () => false,
     handleTsukihimeKeydown: () => false,
+    handleMediaTimingReviewKeydown: () => false,
     handleControllerSelectKeydown: () => {
       controllerSelectKeydownCount += 1;
       return true;

src/renderer/handlers/keyboard.ts

@@ -18,7 +18,7 @@ export function createKeyboardHandlers(
     handleJimakuKeydown: (e: KeyboardEvent) => boolean;
     handleTsukihimeKeydown: (e: KeyboardEvent) => boolean;
     handleYoutubePickerKeydown: (e: KeyboardEvent) => boolean;
-    handleMediaTimingReviewKeydown?: (e: KeyboardEvent) => boolean;
+    handleMediaTimingReviewKeydown: (e: KeyboardEvent) => boolean;
     handlePlaylistBrowserKeydown: (e: KeyboardEvent) => boolean;
     handleControllerSelectKeydown: (e: KeyboardEvent) => boolean;
     handleControllerDebugKeydown: (e: KeyboardEvent) => boolean;
@@ -1080,7 +1080,7 @@ export function createKeyboardHandlers(
 
     document.addEventListener('keydown', (e: KeyboardEvent) => {
       if (ctx.state.mediaTimingReviewModalOpen) {
-        options.handleMediaTimingReviewKeydown?.(e);
+        options.handleMediaTimingReviewKeydown(e);
         return;
       }