fix(player): harden secondary-device audio playback guard

frontend/angular/src/app/features/player/player-shell.component.spec.ts

@@ -400,7 +400,14 @@ describe('PlayerShellComponent gameplay wiring', () => {
     const component = new PlayerShellComponent();
     component.ngOnInit();
 
-    await expect(mediaPrototype.play()).resolves.toBeUndefined();
+    const pause = vi.fn();
+    const audioElement = { muted: false, defaultMuted: false, volume: 1, pause };
+
+    await expect(mediaPrototype.play.call(audioElement)).resolves.toBeUndefined();
+    expect(audioElement.muted).toBe(true);
+    expect(audioElement.defaultMuted).toBe(true);
+    expect(audioElement.volume).toBe(0);
+    expect(pause).toHaveBeenCalledTimes(1);
 
     component.ngOnDestroy();
 

frontend/angular/src/app/features/player/player-shell.component.ts

@@ -16,18 +16,21 @@ interface SessionDetail {
 type ConnectionState = 'online' | 'reconnecting' | 'offline';
 type LoadingTransition = 'refresh' | 'join' | 'submit-lie' | 'submit-guess' | null;
 
+type GuardableMediaElement = {
+  muted?: boolean;
+  defaultMuted?: boolean;
+  volume?: number;
+  pause?: () => void;
+};
+
 type MediaPrototypeWithGuardState = {
-  play?: () => Promise<void>;
+  play?: (this: GuardableMediaElement) => Promise<void>;
   __wppSecondaryDeviceAudioGuard__?: {
-    originalPlay: () => Promise<void>;
+    originalPlay: (this: GuardableMediaElement) => Promise<void>;
     installs: number;
   };
 };
 
-type GuardableMediaElement = {
-  muted?: boolean;
-  pause?: () => void;
-};
 
 function resolveLocalStorage(): Storage | undefined {
   if (typeof window === 'undefined') {
@@ -221,7 +224,15 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
       guardState.installs += 1;
     } else {
       const originalPlay = mediaPrototype.play;
-      mediaPrototype.play = () => Promise.resolve();
+      mediaPrototype.play = function mediaGuardedPlay(this: GuardableMediaElement): Promise<void> {
+        this.muted = true;
+        this.defaultMuted = true;
+        if (typeof this.volume === 'number') {
+          this.volume = 0;
+        }
+        this.pause?.();
+        return Promise.resolve();
+      };
       mediaPrototype.__wppSecondaryDeviceAudioGuard__ = {
         originalPlay,
         installs: 1,
@@ -242,6 +253,7 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
     };
   }
 
+
   private silenceExistingMediaElements(): void {
     if (typeof document === 'undefined' || typeof document.querySelectorAll !== 'function') {
       return;
@@ -258,6 +270,10 @@ export class PlayerShellComponent implements OnInit, OnDestroy {
 
     activeElements.forEach((element) => {
       element.muted = true;
+      element.defaultMuted = true;
+      if (typeof element.volume === 'number') {
+        element.volume = 0;
+      }
       element.pause?.();
     });
   }