feat(chromecast): send custom message for overlay subtitles

src/events.web.tsx

@@ -126,6 +126,27 @@ export const useEvent = <Event extends keyof OmniEvents>(
 		}
 		return undefined;
 	}, [event, player]);
+
+	// ASS/PGS (overlay) subtitle selection is not a videojs text-track change, so
+	// re-fire subtitleChange when the overlay subtitle changes too — consumers
+	// only need useEvent("subtitleChange").
+	useEffect(() => {
+		if (event !== "subtitleChange") return;
+		return player.subscribeOverlaySubtitle(() => {
+			const sel = player.subtitles.find((s) => s.selected);
+			const cb = callbackRef.current as (s: unknown) => void;
+			cb(
+				sel
+					? {
+							id: sel.id,
+							label: sel.label,
+							language: sel.language,
+							selected: true,
+						}
+					: undefined,
+			);
+		});
+	}, [event, player]);
 };
 
 function createMapper<Key extends keyof OmniPlayerState, State, Result>(
@@ -182,7 +203,7 @@ export const stateMapper = {
 		if (!r) return "unavailable";
 		if (r.remotePlaybackState === "connecting") return "connecting";
 		if (r.remotePlaybackState === "connected") return "connected";
-		return r.remotePlaybackAvailability
+		return r.remotePlaybackAvailability;
 	}),
 };