Add anonymous listening support and redesign web-player UI

Backend:
- Expose GET /config/playback so the frontend can detect whether
  anonymous listening is enabled without requiring auth
- Wire anonymous access through track streaming and YouTube resolve flows

Frontend:
- Allow browsing/listening without a session when the backend enables it
- Redesign Inicio, Sidebar and top bar with a new dark theme, typography,
  and layout (top bar with live quick-search, sticky/blurred on scroll)
- Populate Top música, Popular and Recomendados with real Musify +
  YouTube Music data instead of placeholders
- Various shape, spacing, color and animation refinements across the
  redesigned components

web-player/package.json

@@ -35,8 +35,8 @@
 		"vite": "^8.0.16"
 	},
 	"dependencies": {
-		"@fontsource-variable/inter": "^5.2.8",
-		"@fontsource-variable/sora": "^5.3.0",
+		"@fontsource-variable/bricolage-grotesque": "^5.3.0",
+		"@fontsource-variable/manrope": "^5.3.0",
 		"@lucide/svelte": "^1.23.0",
 		"@sveltejs/adapter-node": "^5.5.7",
 		"jose": "^6.2.3",