feat: redesign web interface to match aonsoku layout

Replace the early prototype UI with a darker Aonsoku-inspired shell featuring a compact top bar, library sidebar, command palette, settings overlay, dense track list, artists table, albums grid, and a bottom player bar. Add a supporting albums browse endpoint so the frontend can render the same navigation shape without faking data.

internal/httpapi/router.go

@@ -53,6 +53,7 @@ func NewRouter(cfg config.Config, database *sql.DB, scanService *scanner.Service
 			private.Get("/home", application.home)
 			private.Get("/artists", application.artists)
 			private.Get("/artists/{id}", application.artistByID)
+			private.Get("/albums", application.albums)
 			private.Get("/albums/{id}", application.albumByID)
 			private.Get("/tracks", application.tracks)
 			private.Get("/tracks/{id}", application.trackByID)
@@ -152,6 +153,15 @@ func (a app) artistByID(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, item)
 }
 
+func (a app) albums(w http.ResponseWriter, r *http.Request) {
+	items, err := a.library.Albums(r.Context(), 1000)
+	if err != nil {
+		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load albums"})
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"items": items})
+}
+
 func (a app) albumByID(w http.ResponseWriter, r *http.Request) {
 	item, err := a.library.AlbumByID(r.Context(), chi.URLParam(r, "id"))
 	if err != nil {