fix(portals): fourteenth review round on the cinematic details

- The hero keys its one-time stage/compact decision on a stable content
  identity (provider + id) that every host passes, so a TMDB rename plus
  a late backdrop no longer flips the visible hero.
- An explicit Stalker movie launch joins its host's start generation: it
  supersedes an earlier start and is dropped once a Play, Start Over or
  later launch begins, on the controller, search, collection and catalog
  hosts.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

libs/ui/components/src/lib/content-hero/content-hero.component.spec.ts

@@ -231,6 +231,24 @@ describe('ContentHeroComponent cinematic layout', () => {
         expect(mute?.getAttribute('aria-pressed')).toBe('true');
     });
 
+    it('keys the layout on the content identity when enrichment renames the title', () => {
+        fixture.componentRef.setInput('contentKey', 'm3u:42');
+        fixture.componentRef.setInput('title', 'Channel name');
+        fixture.componentRef.setInput('posterUrl', 'poster.jpg');
+        fixture.detectChanges();
+        expect(host().querySelector('.hero--compact')).toBeTruthy();
+
+        // TMDB replaces the title and brings a backdrop: same content.
+        fixture.componentRef.setInput('title', 'Proper Title (2021)');
+        fixture.componentRef.setInput('backdropUrl', 'wide.jpg');
+        fixture.detectChanges();
+        expect(host().querySelector('.hero--compact')).toBeTruthy();
+
+        fixture.componentRef.setInput('contentKey', 'm3u:43');
+        fixture.detectChanges();
+        expect(host().querySelector('.hero--compact')).toBeNull();
+    });
+
     it('places the actions before the credits slot', () => {
         fixture.componentRef.setInput('title', 'Black Harbor');
         fixture.detectChanges();

libs/ui/components/src/lib/content-hero/content-hero.component.ts

@@ -47,6 +47,11 @@ export class ContentHeroComponent {
     readonly description = input<string>();
     readonly posterUrl = input<string>();
     readonly backdropUrl = input<string>();
+    /**
+     * Stable identity of the shown title (provider + id). The layout is
+     * decided once per identity; enrichment may replace the title itself.
+     */
+    readonly contentKey = input<string | null>(null);
     /** 0–100 watched share; renders the resume bar above the actions. */
     readonly progress = input<number | null>(null);
     /** With the setting on, this trailer plays muted behind the details. */
@@ -87,10 +92,11 @@ export class ContentHeroComponent {
     /**
      * Decided once per title: a backdrop that TMDB enrichment adds a moment
      * later fills the compact hero instead of growing it under the user's
-     * cursor. The title survives the merge; the poster may not.
+     * cursor. Keyed by `contentKey`, falling back to the title for hosts
+     * without one.
      */
     readonly layout = linkedSignal<string | undefined, ContentHeroLayout>({
-        source: () => this.title(),
+        source: () => this.contentKey() ?? this.title(),
         computation: () =>
             untracked(() => this.hasRealBackdrop()) ? 'stage' : 'compact',
     });

libs/ui/components/src/lib/portal-detail-shell/portal-detail-shell.component.html

@@ -9,6 +9,7 @@
             [backdropUrl]="backdropUrl()"
             [progress]="progress()"
             [trailerBackdropUrl]="trailerBackdropUrl()"
+            [contentKey]="contentKey()"
             [isLoading]="isLoading()"
             [errorMessage]="errorMessage()"
         >

libs/ui/components/src/lib/portal-detail-shell/portal-detail-shell.component.ts

@@ -73,6 +73,8 @@ export class PortalDetailShellComponent {
     readonly progress = input<number | null>(null);
     /** Trailer embed to play muted behind the hero, when the setting is on. */
     readonly trailerBackdropUrl = input<string | null>(null);
+    /** Stable identity of the shown title; see `ContentHeroComponent.contentKey`. */
+    readonly contentKey = input<string | null>(null);
     readonly isLoading = input(false);
     readonly errorMessage = input<string>();
     readonly backLabel = input<string>();