fix(playback): re-evaluate the wake lock after a rejection masked a state change

In the PWA path a hidden-visible round-trip (or pause/resume) while
wakeLock.request() was pending got swallowed by the in-flight guard; if
that request then rejected, only the flag was cleared and a continuously
playing visible video sat without a wake lock until the next unrelated
event. State changes arriving mid-flight now queue one re-evaluation on
rejection; permanent denials still don't loop because nothing queues a
retry without a fresh interleaved change. Review finding by Codex.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/web/src/app/services/playback-keep-awake.service.spec.ts

@@ -248,6 +248,38 @@ describe('PlaybackKeepAwakeService', () => {
             expect(request).toHaveBeenCalledTimes(2);
         });
 
+        it('re-evaluates after a rejection that masked a state change', async () => {
+            let rejectRequest: ((reason: Error) => void) | undefined;
+            request.mockImplementationOnce(
+                () =>
+                    new Promise((_resolve, reject) => {
+                        rejectRequest = reject;
+                    })
+            );
+
+            video.dispatchEvent(new Event('playing'));
+            // Hidden→visible round-trip while request() is still pending:
+            // both sync() calls are swallowed by the in-flight guard, and
+            // the pending request rejects because of the hidden moment.
+            setVisibility('hidden');
+            setVisibility('visible');
+            rejectRequest?.(new Error('document was hidden'));
+            await flush();
+
+            // The masked state change must trigger a fresh request — the
+            // video is still playing in a visible document.
+            expect(request).toHaveBeenCalledTimes(2);
+        });
+
+        it('does not retry a plain rejection with no interleaved change', async () => {
+            request.mockRejectedValueOnce(new Error('denied'));
+
+            video.dispatchEvent(new Event('playing'));
+            await flush();
+
+            expect(request).toHaveBeenCalledTimes(1);
+        });
+
         it('survives a denied wake lock request', async () => {
             request.mockRejectedValueOnce(new Error('denied'));
 

apps/web/src/app/services/playback-keep-awake.service.ts

@@ -54,6 +54,7 @@ export class PlaybackKeepAwakeService {
     private lastSentToBridge: boolean | null = null;
     private wakeLock: WakeLockSentinelLike | null = null;
     private wakeLockRequestInFlight = false;
+    private wakeLockRetryQueued = false;
 
     private readonly onPlaying = (event: Event) => {
         const target = event.target;
@@ -165,7 +166,15 @@ export class PlaybackKeepAwakeService {
     }
 
     private acquireWakeLock(): void {
-        if (this.wakeLock || this.wakeLockRequestInFlight) {
+        if (this.wakeLock) {
+            return;
+        }
+        if (this.wakeLockRequestInFlight) {
+            // A state change arrived while request() is still pending (e.g.
+            // hidden→visible round-trip). The pending request may reject
+            // because of the moment it was processed in, so remember to
+            // re-evaluate once it settles instead of dropping this signal.
+            this.wakeLockRetryQueued = true;
             return;
         }
         const wakeLock = (navigator as WakeLockNavigator).wakeLock;
@@ -177,6 +186,9 @@ export class PlaybackKeepAwakeService {
             .request('screen')
             .then((sentinel) => {
                 this.wakeLockRequestInFlight = false;
+                // The resolve path re-reads current state below, which
+                // covers whatever change queued the retry.
+                this.wakeLockRetryQueued = false;
                 // The browser releases the sentinel on its own when the page
                 // hides; forget it so the next sync() can re-request.
                 sentinel.addEventListener?.('release', () => {
@@ -191,9 +203,16 @@ export class PlaybackKeepAwakeService {
                 this.wakeLock = sentinel;
             })
             .catch(() => {
-                // Denied (battery saver, hidden document, …) — a later
-                // `playing` or visibility event retries via sync().
                 this.wakeLockRequestInFlight = false;
+                if (this.wakeLockRetryQueued) {
+                    // A state change was masked by the in-flight request —
+                    // re-evaluate now. Permanent denials don't loop: without
+                    // a fresh interleaved change nothing queues a retry.
+                    this.wakeLockRetryQueued = false;
+                    this.sync();
+                }
+                // Otherwise: denied (battery saver, hidden document, …) — a
+                // later `playing` or visibility event retries via sync().
             });
     }