fix(library): scoped live search FTS, race, and multi-server advanced search (#868)

* fix(library): scoped live search FTS, race, and multi-server advanced search

Scope track_fts live search to active server_id so multi-server libraries
no longer show empty or wrong-server hits. Match Navidrome-style any-word
prefix matching and GROUP BY artist/album dedupe on track_fts only.

Frontend: parallel local vs search3 race (empty waits, 8s network timeout),
merge supplemental hits after both settle, debug via Settings → Logging →
Debug (frontend_debug_log). Advanced Search FTS subqueries use the same
server scope fix.

* docs: CHANGELOG and credits for PR #868 live search fix

src/api/subsonicSearch.ts

@@ -22,6 +22,7 @@ export async function search(
     artistCount?: number;
     songCount?: number;
     signal?: AbortSignal;
+    timeout?: number;
   },
 ): Promise<SearchResults> {
   if (!query.trim()) return { artists: [], albums: [], songs: [] };
@@ -40,7 +41,7 @@ export async function search(
       songCount: options?.songCount ?? 10,
       ...libraryFilterParams(),
     },
-    15000,
+    options?.timeout ?? 15000,
     options?.signal,
   );
   const r = data.searchResult3 ?? {};