The HTTP endpoint approach still crashed due to Wails asset server
issues. Replaced with a pure frontend solution: searchLibraryCache()
does a substring match against the libraryStore's cached artists and
albums arrays. This is pure JS — zero Go calls, zero RPC, zero
network — guaranteed instant.
Results appear immediately as the user types. The full MB+LB search
pipeline still runs via Wails RPC and replaces the library matches
with richer results when done.
Added cachedArtists/cachedAlbums getters to LibraryStore for
synchronous read-only access to the already-loaded data.
Removed the /api/search-local HTTP handler from the backend.