fix(playback): tear down the Shaka engine on critical error events too

A non-recoverable Shaka error emitted after a successful load left the
dead engine attached to the media element and exposed to the
shared-controls bridge (Greptile P1, round 2). Critical error events now
destroy the player right after the diagnostic is emitted, matching the
load-failure path.

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

libs/ui/playback/src/lib/shaka-engine/shaka-video-session.spec.ts

@@ -102,10 +102,14 @@ describe('ShakaVideoSession', () => {
         const player = environment.instances[0];
         player.dispatch('error', { severity: 1, category: 1, code: 1002 });
         expect(issues).toEqual([]);
+        expect(session.getPlayer()).toBe(player);
 
         player.dispatch('error', { severity: 2, category: 6, code: 6001 });
         expect(issues).toHaveLength(1);
         expect(issues[0].code).toBe(PlaybackDiagnosticCode.DrmOrEncryption);
+        // Critical errors end playback: the dead engine must be torn down.
+        expect(player.destroyCount).toBe(1);
+        expect(session.getPlayer()).toBeNull();
     });
 
     it('emits a diagnostic and tears the engine down when load rejects', async () => {

libs/ui/playback/src/lib/shaka-engine/shaka-video-session.ts

@@ -236,6 +236,9 @@ export class ShakaVideoSession {
             this.config.emitPlaybackIssue(
                 classifyShakaPlaybackIssue(detail, this.createMetadata(url))
             );
+            // Critical errors end playback; never leave the dead engine
+            // attached or exposed to the shared-controls bridge.
+            this.beginPlayerTeardown();
         };
         const refreshListener = (): void => {
             if (!this.isStale(generation) && this.player === player) {