feat: import library from media root and stream tracks

Add a filesystem scanner that ingests supported audio files from MEDIA_ROOT into SQLite using embedded tags with filename fallbacks. Wire startup scanning, manual rescan, and authenticated audio streaming into the backend, then connect the web player to the real stream endpoint.

internal/httpapi/router.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
+	"os"
 	"strings"
 	"time"
 
@@ -13,18 +14,21 @@ import (
 	"github.com/benya/temporserv/internal/auth"
 	"github.com/benya/temporserv/internal/config"
 	"github.com/benya/temporserv/internal/library"
+	"github.com/benya/temporserv/internal/scanner"
 	"github.com/benya/temporserv/internal/subsonic"
 )
 
 type app struct {
 	auth    *auth.Service
 	library *library.Service
+	scanner *scanner.Service
 }
 
-func NewRouter(cfg config.Config, database *sql.DB) http.Handler {
+func NewRouter(cfg config.Config, database *sql.DB, scanService *scanner.Service) http.Handler {
 	application := app{
 		auth:    auth.NewService(database),
 		library: library.NewService(database),
+		scanner: scanService,
 	}
 
 	r := chi.NewRouter()
@@ -48,7 +52,10 @@ func NewRouter(cfg config.Config, database *sql.DB) http.Handler {
 			private.Get("/me", application.me)
 			private.Get("/home", application.home)
 			private.Get("/tracks", application.tracks)
+			private.Post("/admin/scan", application.scanLibrary)
 		})
+
+		api.Get("/stream/{id}", application.streamTrack)
 	})
 
 	r.Route("/rest", func(rest chi.Router) {
@@ -133,6 +140,49 @@ func (a app) subsonicRandomSongs(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, subsonic.RandomSongsResponse(tracks))
 }
 
+func (a app) scanLibrary(w http.ResponseWriter, r *http.Request) {
+	result, err := a.scanner.Scan(r.Context())
+	if err != nil {
+		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
+		return
+	}
+	writeJSON(w, http.StatusOK, result)
+}
+
+func (a app) streamTrack(w http.ResponseWriter, r *http.Request) {
+	token := r.URL.Query().Get("token")
+	if token == "" {
+		token = strings.TrimSpace(strings.TrimPrefix(r.Header.Get("Authorization"), "Bearer "))
+	}
+
+	if _, err := a.auth.CurrentUserByToken(r.Context(), token); err != nil {
+		writeJSON(w, http.StatusUnauthorized, map[string]string{"error": "unauthorized"})
+		return
+	}
+
+	track, err := a.library.TrackByID(r.Context(), chi.URLParam(r, "id"))
+	if err != nil {
+		writeJSON(w, http.StatusNotFound, map[string]string{"error": "track not found"})
+		return
+	}
+
+	file, err := os.Open(track.FilePath)
+	if err != nil {
+		writeJSON(w, http.StatusNotFound, map[string]string{"error": "audio file not available"})
+		return
+	}
+	defer file.Close()
+
+	info, err := file.Stat()
+	if err != nil {
+		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to stat file"})
+		return
+	}
+
+	w.Header().Set("Content-Type", track.ContentType)
+	http.ServeContent(w, r, info.Name(), info.ModTime(), file)
+}
+
 func writeJSON(w http.ResponseWriter, status int, payload any) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(status)