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>

libs/shared/interfaces/src/lib/electron-api.interface.ts

@@ -32,6 +32,10 @@ import {
 } from './portal-playback.interface';
 import { PortalDebugEvent } from './portal-debug.interface';
 import { CatalogTitleMatch } from './catalog-title-match.interface';
+import {
+    VodSourceCandidateRow,
+    VodSourcePin,
+} from './vod-source.interface';
 import { Settings } from './settings.interface';
 import {
     TmdbCacheEntry,
@@ -254,8 +258,17 @@ export interface ElectronBridgeXtreamCancelResult extends ElectronBridgeResult {
 }
 
 export interface ElectronBridgeXtreamProbeResult {
+    /**
+     * HTTP status, or 0 when no response was obtained.
+     *
+     * 0 covers a timeout and a URL rejected by the redirect-safety policy as
+     * well as a dead host, so it means "could not check" — never "offline".
+     */
     status: number;
     url: string;
+    /** Round-trip time; present whenever the request completed either way. */
+    latencyMs?: number;
+    error?: string;
 }
 
 export interface ElectronBridgeEpgFetchResult extends ElectronBridgeResult {
@@ -672,6 +685,11 @@ export interface ElectronBridgeApi {
         url: string,
         method?: 'GET' | 'HEAD'
     ) => Promise<ElectronBridgeXtreamProbeResult>;
+    /** Generic stream reachability probe (VOD multi-source availability) */
+    probeStreamUrl: (
+        url: string,
+        method?: 'GET' | 'HEAD'
+    ) => Promise<ElectronBridgeXtreamProbeResult>;
     refreshPlaylist: (
         payload: PlaylistRefreshPayload
     ) => Promise<Playlist | PlaylistRefreshCancelledResult>;
@@ -849,6 +867,18 @@ export interface ElectronBridgeApi {
     >;
     /** Cross-playlist title matching (actor page "All portals" scope) */
     dbMatchTitles: (titles: string[]) => Promise<CatalogTitleMatch[]>;
+    /** VOD multi-source: the same movie in the user's other Xtream playlists */
+    dbFindTitleSources: (request: {
+        title: string;
+        year?: number | null;
+        excludePlaylistId?: string | null;
+    }) => Promise<VodSourceCandidateRow[]>;
+    /** Per-movie pinned source; keys are passed most-trusted first */
+    dbGetVodSourcePin: (matchKeys: string[]) => Promise<VodSourcePin | null>;
+    dbSetVodSourcePin: (pin: VodSourcePin) => Promise<ElectronBridgeResult>;
+    dbClearVodSourcePin: (
+        matchKeys: string[]
+    ) => Promise<ElectronBridgeResult>;
     onChannelChange?: (
         callback: (data: { direction: 'up' | 'down' }) => void
     ) => () => void;