Controller: hold to show the secondary subtitle, dictionary entry navigation, standard button names (#312)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

src/shared/ipc/validators.ts

@@ -217,6 +217,9 @@ function parseControllerBindings(value: unknown): ControllerConfigUpdate['bindin
     'nextAudio',
     'playCurrentAudio',
     'toggleMpvPause',
+    'holdSecondarySub',
+    'previousEntry',
+    'nextEntry',
   ] as const;
   for (const key of discreteKeys) {
     if (value[key] === undefined) continue;