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

.claude/launch.json

@@ -0,0 +1,17 @@
+{
+	"version": "0.0.1",
+	"configurations": [
+		{
+			"name": "musify-web",
+			"runtimeExecutable": "npm",
+			"runtimeArgs": ["--prefix", "web-player", "run", "dev", "--", "--port", "3000"],
+			"port": 3000
+		},
+		{
+			"name": "musify-api",
+			"runtimeExecutable": "dotnet",
+			"runtimeArgs": ["run", "--project", "backend/Hosts/Musify.Api"],
+			"port": 5111
+		}
+	]
+}