fix(portals): a failed MPV/VLC movie launch is reported to the viewer

The launch settlement swallowed a rejected launch together with a
superseded one, so the menu's launch had nothing to report. It now hands
a failure that nothing superseded to the page, which logs it and shows
the playback error.

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

libs/portal/xtream/feature/src/lib/vod-details/vod-details-external-launch.ts

@@ -5,6 +5,8 @@ interface OwnedExternalLaunchOptions {
     owns: () => boolean;
     close: (session: ExternalPlayerSession) => Promise<void>;
     warnCloseFailure: (error: unknown) => void;
+    /** The launch itself failed while nothing superseded it: the user's to hear about. */
+    reportLaunchFailure?: (error: unknown) => void;
     clearPending: () => void;
     clearOwnership: () => void;
 }
@@ -38,7 +40,10 @@ export async function settleOwnedExternalLaunch(
         options.clearPending();
         options.clearOwnership();
         return false;
-    } catch {
+    } catch (error) {
+        if (options.owns()) {
+            options.reportLaunchFailure?.(error);
+        }
         // A partial reuse can reject while Electron retains a matching
         // closable error session. Keep its credential-free identity so the
         // next source start can still find and close that exact process.

libs/portal/xtream/feature/src/lib/vod-details/vod-details-external-playback.spec.ts

@@ -211,6 +211,45 @@ describe('VodDetailsPlaybackService — external playback handoff', () => {
         expect(openResolvedPlayback).toHaveBeenCalledTimes(1);
     });
 
+    it('reports a failed launch to the page unless another start superseded it', async () => {
+        const reportExternalLaunchFailure = jest.fn();
+        service.bind({
+            vodId: routeVodId,
+            vodInfo: signal(null),
+            activeSource,
+            supersedePendingSwitch: jest.fn(),
+            reportExternalLaunchFailure,
+        });
+        const failure = new Error('mpv is not installed');
+        const playback = {
+            streamUrl: 'https://example.com/alt.mkv',
+            title: 'Example Movie',
+            contentInfo: {
+                playlistId: 'playlist-1',
+                contentXtreamId: 1,
+                contentType: 'vod' as const,
+            },
+        };
+
+        openResolvedPlayback.mockRejectedValueOnce(failure);
+        await service.startResolvedPlayback(playback);
+        expect(reportExternalLaunchFailure).toHaveBeenCalledWith(failure);
+
+        // The route moved on before the failure arrived: the error belongs
+        // to a launch nothing shows any more.
+        let shown = true;
+        let rejectLaunch: (error: Error) => void = () => undefined;
+        openResolvedPlayback.mockImplementationOnce(
+            () => new Promise((_, reject) => (rejectLaunch = reject))
+        );
+        const stale = service.startResolvedPlayback(playback, () => shown);
+        await new Promise((resolve) => setTimeout(resolve));
+        shown = false;
+        rejectLaunch(failure);
+        await expect(stale).resolves.toBe(false);
+        expect(reportExternalLaunchFailure).toHaveBeenCalledTimes(1);
+    });
+
     it('closes a closable error before starting a replacement source', async () => {
         activeSession.set({
             ...sessionFor(ROUTE_PLAYLIST, ROUTE_VOD_ID),

libs/portal/xtream/feature/src/lib/vod-details/vod-details-playback.service.ts

@@ -57,6 +57,8 @@ export interface VodDetailsPlaybackBindings {
     activeSource?: Signal<PlayerContentInfo | null>;
     /** Retires a source resolution that the accepted fallback now supersedes. */
     supersedePendingSwitch: () => void;
+    /** An MPV/VLC launch failed while nothing superseded it; the page tells the user. */
+    reportExternalLaunchFailure?: (error: unknown) => void;
 }
 
 /**
@@ -532,6 +534,8 @@ export class VodDetailsPlaybackService {
                     'Closing a superseded external player failed.',
                     error
                 ),
+            reportLaunchFailure: (error) =>
+                this.bindings()?.reportExternalLaunchFailure?.(error),
             clearPending: () => this.clearExternalLaunchPending(generation),
             clearOwnership: () => this.clearExternalLaunchOwnership(generation),
         });

libs/portal/xtream/feature/src/lib/vod-details/vod-details-route.component.ts

@@ -420,6 +420,14 @@ export class VodDetailsRouteComponent implements OnInit, OnDestroy {
             activeSource: this.msUi.activeAlternativeSource,
             supersedePendingSwitch: () =>
                 this.multiSource.supersedePendingSwitch(),
+            reportExternalLaunchFailure: (error) => {
+                this.logger.error('External launch failed', error);
+                this.snackBar.open(
+                    this.translateService.instant('PORTALS.PLAYBACK_ERROR'),
+                    undefined,
+                    { duration: 3000 }
+                );
+            },
         });
 
         effect(() => {