feat(api): library sources, scanner and catalog (M2)

- schema for sources, path patterns, media files, artists, albums,
  tracks, genres (migration 00003)
- path patterns (RE2 with named groups, skip), merge with tags by
  source priority, fallbacks from the file name and folder, name
  normalization and multi-artist split
- scanner: walk, skip unchanged files by size and mtime, ffprobe in 8
  workers with a single catalog writer, renames by content hash keep
  the track, duplicates fold into one track with the best file as
  primary, missing files are kept 30 days
- storage-agent mounts NFS with validated server, export and an option
  whitelist, no shell; test mount counts audio files
- admin API: sources CRUD, connection test, patterns with preview,
  scan, library status, file errors, host folder picker; scheduled
  scans and health checks; mounts are restored on start
- catalog API: artist, artist albums, album with tracks, track
- api image is alpine with ffmpeg for ffprobe

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

services/api/internal/server/router.go

@@ -10,6 +10,7 @@ import (
 
 	"pipu/api/internal/api/gen"
 	"pipu/api/internal/auth"
+	"pipu/api/internal/library"
 	"pipu/api/internal/platform/httpx"
 	"pipu/api/internal/system"
 )
@@ -19,6 +20,8 @@ type Deps struct {
 	Log    *slog.Logger
 	System *system.Handler
 	Auth   *auth.Handler
+	// Library — хранилища, сканы и каталог.
+	Library *library.Handler
 	// AuthService проверяет access-токены в middleware. nil — только для тестов служебных эндпоинтов.
 	AuthService *auth.Service
 }
@@ -27,13 +30,15 @@ type Deps struct {
 // По мере появления модулей (catalog, ...) они встраиваются сюда.
 // Алиасы дают встроенным полям разные имена: у модулей одинаковое имя типа Handler.
 type (
-	systemHandler = system.Handler
-	authHandler   = auth.Handler
+	systemHandler  = system.Handler
+	authHandler    = auth.Handler
+	libraryHandler = library.Handler
 )
 
 type handlers struct {
 	*systemHandler
 	*authHandler
+	*libraryHandler
 }
 
 var _ gen.StrictServerInterface = handlers{}
@@ -53,7 +58,7 @@ func NewRouter(d Deps) http.Handler {
 	r.NotFound(httpx.NotFound)
 	r.MethodNotAllowed(httpx.MethodNotAllowed)
 
-	strict := gen.NewStrictHandlerWithOptions(handlers{systemHandler: d.System, authHandler: d.Auth}, nil, gen.StrictHTTPServerOptions{
+	strict := gen.NewStrictHandlerWithOptions(handlers{systemHandler: d.System, authHandler: d.Auth, libraryHandler: d.Library}, nil, gen.StrictHTTPServerOptions{
 		RequestErrorHandlerFunc:  httpx.RequestError,
 		ResponseErrorHandlerFunc: httpx.ResponseError(log),
 	})