feat(api): search with Meilisearch (M2)

- artists, albums and tracks indexes are rebuilt from PostgreSQL next
  to the live ones and swapped in, so search keeps working; a rebuild
  runs on start, after every scan and when a source is removed
- transliteration fields (Кино ↔ kino) and a retry in the other
  keyboard layout (ghbdtn → привет) reported as corrected_query
- /search/suggest (3 artists, 3 albums, 5 tracks), /search by type
  with cursor pages, /admin/search/reindex; Meilisearch is part of
  /readyz
- found ids are hydrated from the catalog, so a lagging index never
  returns deleted entries

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

services/api/cmd/api/main.go

@@ -20,6 +20,7 @@ import (
 	"pipu/api/internal/platform/config"
 	"pipu/api/internal/platform/db"
 	"pipu/api/internal/platform/httpx"
+	"pipu/api/internal/search"
 	"pipu/api/internal/server"
 	"pipu/api/internal/system"
 )
@@ -78,6 +79,7 @@ func run() error {
 	}, log, map[string]system.Checker{
 		"postgres": system.CheckerFunc(pool.Ping),
 		"redis":    system.CheckerFunc(func(ctx context.Context) error { return rdb.Ping(ctx).Err() }),
+		"search":   system.CheckerFunc(search.NewMeili(cfg.MeiliURL, cfg.MeiliMasterKey).Healthy),
 	})
 
 	libStore := library.NewStore(pool)
@@ -86,6 +88,11 @@ func run() error {
 	scanner := library.NewScanner(libStore, prober, board, log)
 	libSvc := library.NewService(libStore, scanner, board, library.NewHTTPAgent(cfg.StorageAgentURL, cfg.InternalToken),
 		prober, library.Config{LibraryRoot: cfg.LibraryRoot, HostRoot: cfg.LibraryHostRoot}, log)
+	meili := search.NewMeili(cfg.MeiliURL, cfg.MeiliMasterKey)
+	indexer := search.NewIndexer(pool, meili, log)
+	scanner.AfterScan = func(context.Context) { indexer.Trigger() }
+	libSvc.OnCatalogChanged = indexer.Trigger
+	indexer.Trigger() // индекс мог отстать (новая версия, сбой Meilisearch) — пересобираем при старте
 	go libSvc.Restore(ctx)
 	go libSvc.RunSchedule(ctx)
 
@@ -95,6 +102,7 @@ func run() error {
 		Auth:        auth.NewHandler(authSvc, cfg.CookieSecure),
 		AuthService: authSvc,
 		Library:     library.NewHandler(libSvc, libStore),
+		Search:      search.NewHandler(meili, libStore, indexer, log),
 	}))
 	log.Info("starting", "version", buildinfo.Version)
 	return httpx.Serve(ctx, log, srv, cfg.ShutdownTimeout)