feat(api): add /api/lidarr/search proxy with library/request enrichment

Implements GET /api/lidarr/search?q=&kind=artist|album|track. Validates
kind and q, loads lidarr_config per-request, calls the matching Lidarr
Lookup* method, enriches each result with in_library (EXISTS by MBID
against artists/albums/tracks) and requested (HasNonTerminalRequestForMBID),
and returns a normalized JSON array. Adds lidarrCfg field to handlers struct
and threads lidarrconfig.Service through Mount and server.Router.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/api/auth_test.go

@@ -22,6 +22,7 @@ import (
 	"git.fabledsword.com/bvandeusen/minstrel/internal/db"
 	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
 	"git.fabledsword.com/bvandeusen/minstrel/internal/dbtest"
+	"git.fabledsword.com/bvandeusen/minstrel/internal/lidarrconfig"
 	"git.fabledsword.com/bvandeusen/minstrel/internal/playevents"
 )
 
@@ -54,7 +55,7 @@ func testHandlers(t *testing.T) (*handlers, *pgxpool.Pool) {
 		ContextWeight: 2.0, SimilarityWeight: 2.0,
 		RecentlyPlayedHours: 1, RadioSize: 50, RadioSizeMax: 200,
 	}
-	h := &handlers{pool: pool, logger: logger, events: w, recCfg: recCfg, rng: func() float64 { return 0.5 }}
+	h := &handlers{pool: pool, logger: logger, events: w, recCfg: recCfg, rng: func() float64 { return 0.5 }, lidarrCfg: lidarrconfig.New(pool)}
 	return h, pool
 }