feat: manual EPG-to-channel mapping with mapping fallback (#1165)

* feat(epg): manual EPG-to-channel mapping with mapping fallback in all EPG paths

* fix: epg mapping in live tv list

* fix(epg): harden manual EPG mapping — upgrade safety, perf, playlist-scoped keys

Follow-up fixes on top of the manual EPG-to-channel mapping feature:

- epg-database: dedupe existing epg_programs rows before creating the
  unique (channel_id, start, title) index — a plain CREATE UNIQUE INDEX
  crashed the EPG worker on upgrade when historical duplicates exist;
  replace INSERT OR REPLACE with ON CONFLICT DO UPDATE so the
  epg_programs_fts delete trigger is not bypassed (REPLACE skips delete
  triggers unless recursive_triggers is on), with a plain-INSERT
  fallback when the index cannot be created
- db: add idx_content_epg_channel — the mapping fallback scanned the
  whole content table on every single-channel EPG lookup
- keys: scope Xtream mapping keys per playlist via shared
  buildXtreamEpgMappingKey (xtream:{playlistId}:{id}) — bare stream ids
  collide across portals; the backend fallback now joins categories to
  resolve the playlist id
- pwa: hide "Map EPG channel" entries behind the supportsEpgMapping
  capability — the menu item was a dead end in the PWA
- parser: parse the XMLTV offset sign from the string — Math.sign(0)
  dropped the minutes of ±00:xx offsets
- cleanup: typed window.electron access instead of ad-hoc casts, drop
  unused resolveChannelId and dialog data field, shared
  EpgMappingDialogComponent.open() for all seven call sites
- dialog UX: minimum-characters search hint, save/remove snackbars,
  current mapping shows the EPG channel display name,
  takeUntilDestroyed on the search stream
- i18n: fill the new keys in all 17 locales
- tests: cover mapping CRUD/search escaping, the dedup-index guard,
  offset parsing and playlist-scoped keys; update stale stream-resolver
  specs for the new 50-item limit and 10s timeout

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

* fix(epg): escape backslashes in EPG channel search LIKE pattern

CodeQL js/incomplete-sanitization: a lone trailing backslash in the
search term paired with the closing wildcard under the ESCAPE clause
and corrupted the pattern.

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

* perf(epg): batch mapping lookups in the viewport preview queue

Expose the existing getEpgMappingsBatch operation over a new
EPG_MAPPING_GET_BATCH IPC channel and use it in resolveManualMappings —
the per-entry lookup issued one IPC round-trip per visible channel on
every scroll event.

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

* perf(epg): batch mapping prefetch in the collection preview loader

Resolve all candidate mapping keys for an Xtream preview batch with a
single getEpgMappingsBatch IPC call instead of per-channel lookups.
Also fix a worker early-exit: a channel without tvgId/name returned out
of the shared-iterator loop and silently killed one of the three
concurrent preview workers.

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

---------

Co-authored-by: 4gray <serega05@gmail.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

libs/shared/interfaces/src/index.ts

@@ -7,6 +7,7 @@ export * from './lib/epg-channel-metadata.model';
 export * from './lib/epg-channel-with-programs.interface';
 export * from './lib/epg-channel.model';
 export * from './lib/epg-item.interface';
+export * from './lib/epg-mapping-key.util';
 export * from './lib/epg-program.model';
 export * from './lib/external-player-arguments.utils';
 export * from './lib/external-player-session.interface';

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

@@ -266,6 +266,19 @@ export interface ElectronBridgeEpgFreshnessResult {
     freshUrls: string[];
 }
 
+export interface ElectronBridgeEpgMapping {
+    id: number;
+    channelKey: string;
+    epgChannelId: string;
+    playlistId: string | null;
+}
+
+export interface ElectronBridgeEpgSearchResult {
+    id: string;
+    displayName: string;
+    iconUrl: string | null;
+}
+
 export interface ElectronBridgeEpgLookupOptions {
     sourceUrls?: string[];
 }
@@ -616,6 +629,25 @@ export interface ElectronBridgeApi {
         searchTerm: string,
         limit?: number
     ) => Promise<EpgProgram[]>;
+
+    // EPG channel mapping (manual user overrides)
+    getEpgMapping: (
+        channelKey: string
+    ) => Promise<ElectronBridgeEpgMapping | null>;
+    getEpgMappingsBatch: (
+        channelKeys: string[]
+    ) => Promise<Record<string, string>>;
+    setEpgMapping: (
+        channelKey: string,
+        epgChannelId: string,
+        playlistId?: string
+    ) => Promise<ElectronBridgeResult>;
+    deleteEpgMapping: (channelKey: string) => Promise<ElectronBridgeResult>;
+    searchEpgChannels: (
+        searchTerm: string,
+        limit?: number
+    ) => Promise<ElectronBridgeEpgSearchResult[]>;
+
     updateSettings: (settings: Partial<Settings>) => Promise<void>;
     getAiSettings: () => Promise<ElectronBridgeAiSettings>;
     setMpvPlayerPath: (mpvPlayerPath: string) => Promise<void>;

libs/shared/interfaces/src/lib/epg-mapping-key.util.spec.ts

@@ -0,0 +1,21 @@
+import { buildXtreamEpgMappingKey } from './epg-mapping-key.util';
+
+describe('buildXtreamEpgMappingKey', () => {
+    it('scopes the key to the playlist', () => {
+        expect(buildXtreamEpgMappingKey('playlist-a', 12345)).toBe(
+            'xtream:playlist-a:12345'
+        );
+    });
+
+    it('produces distinct keys for the same stream id in different playlists', () => {
+        expect(buildXtreamEpgMappingKey('playlist-a', 12345)).not.toBe(
+            buildXtreamEpgMappingKey('playlist-b', 12345)
+        );
+    });
+
+    it('accepts string stream ids', () => {
+        expect(buildXtreamEpgMappingKey('playlist-a', '42')).toBe(
+            'xtream:playlist-a:42'
+        );
+    });
+});

libs/shared/interfaces/src/lib/epg-mapping-key.util.ts

@@ -0,0 +1,21 @@
+/**
+ * Key helpers for the manual EPG channel mapping table
+ * (`epg_channel_mappings`).
+ *
+ * M3U channels use their EPG lookup key (tvg-id, falling back to the
+ * channel name) directly — those identifiers are meaningful across
+ * playlists, so a mapping saved once applies everywhere.
+ *
+ * Xtream stream IDs, on the other hand, are provider-local integers:
+ * stream 12345 in portal A has nothing to do with stream 12345 in
+ * portal B. Mapping keys for Xtream channels therefore embed the
+ * playlist ID so mappings never leak across portals. Shared between the
+ * renderer and the Electron main process/worker, like
+ * `title-normalization.util.ts`.
+ */
+export function buildXtreamEpgMappingKey(
+    playlistId: string,
+    xtreamId: number | string
+): string {
+    return `xtream:${playlistId}:${xtreamId}`;
+}