feat(portals): find the same movie in your other playlists

A movie that exists in several imported Xtream playlists now shows a
"Sources N" chip on its detail page and in the player. Switching playlist
mid-film keeps the timecode, a preferred source can be pinned per movie, and
a failed stream offers the alternatives instead of a dead end.

The governing rule is that a guess is never presented as a fact. Every
metadata value carries where it came from — `api` (the provider said so),
`parsed` (inferred from the title) or `probe` (we contacted the stream).
Facts render as plain tags, guesses are prefixed `~` in a warning colour, and
an unknown value renders no tag at all plus a "check" affordance. Ranking and
failover read through `factualOnly()`, so a filename claiming 4K is
structurally unable to outrank a source that was actually reached. A probe
that could not complete reports "unknown", never "unavailable".

Scope is deliberately narrow: Xtream to Xtream, movies only, Electron only.
Stalker never reaches the `content` table and M3U is a JSON blob whose search
forces live content; both are additive later, since the candidate type
already carries all three portal kinds. In the PWA every entry point is gated
off and the chip renders nothing.

Auto-failover is opt-in and off by default. Each source is tried at most once
per session, so it terminates structurally, and the switch is never silent —
the toast names the new playlist, offers an undo, and warns that the dub may
differ only when both sides state an audio track as fact.

Notable details:
- Playlist names are routinely the pasted URL, credentials included. They are
  never rendered raw; a short host-only label is derived instead.
- Quality is derived from pixel width, not height: a 2.39:1 1080p master is
  1920x800, and bucketing that by height would publish "720p" as a fact.
- Switching is a single `inlinePlayback.set()` so the player and engine
  survive and re-seek; the carried position is read before the 15s
  persistence throttle so it does not rewind.
- Sources from one playlist collapse into a group, since the same film often
  appears there several times under different stream ids.

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

apps/web/src/app/settings/settings.component.ts

@@ -20,6 +20,7 @@ import { Router } from '@angular/router';
 import { SettingsContextService } from '@iptvnator/workspace/shell/util';
 import { TranslateModule, TranslateService } from '@ngx-translate/core';
 import { RuntimeCapabilitiesService } from '@iptvnator/services';
+import { VodSourceDiscoveryService } from '@iptvnator/portal/shared/data-access';
 import { Language, StreamFormat } from '@iptvnator/shared/interfaces';
 import { BUILD_COMMIT } from '../../environments/build-commit';
 import { SettingsAboutSectionComponent } from './settings-about-section.component';
@@ -104,6 +105,7 @@ export class SettingsComponent implements OnInit, OnDestroy {
     private readonly settingsCtx = inject(SettingsContextService);
     private readonly settingsSnackbar = inject(SettingsSnackbarService);
     private readonly runtime = inject(RuntimeCapabilitiesService);
+    private readonly vodSourceDiscovery = inject(VodSourceDiscoveryService);
     private readonly matDialog = inject(MatDialog);
     private readonly router = inject(Router);
     private readonly translate = inject(TranslateService);
@@ -129,6 +131,7 @@ export class SettingsComponent implements OnInit, OnDestroy {
         this.runtime.supportsManagedExternalPlayers;
     readonly supportsExternalPlayerPathSettings =
         this.runtime.supportsExternalPlayerPathSettings;
+    readonly supportsVodMultiSource = this.vodSourceDiscovery.isAvailable;
     readonly supportsRemoteControl = this.runtime.supportsRemoteControl;
 
     readonly activeSection = this.settingsCtx.activeSection;