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/src/routes/layout.css

@@ -1,8 +1,8 @@
 @import 'tailwindcss';
 
 @theme {
-	--font-sans: 'Inter Variable', ui-sans-serif, system-ui, sans-serif;
-	--font-display: 'Sora Variable', 'Inter Variable', ui-sans-serif, system-ui, sans-serif;
+	--font-sans: 'Manrope Variable', ui-sans-serif, system-ui, sans-serif;
+	--font-display: 'Bricolage Grotesque Variable', ui-sans-serif, system-ui, sans-serif;
 
 	--color-bg: var(--mf-bg);
 	--color-elevated: var(--mf-elevated);
@@ -19,6 +19,8 @@
 	--color-muted: var(--mf-text-4);
 	--color-accent: var(--mf-accent);
 	--color-accent-soft: var(--mf-accent-soft);
+	--color-accent-glow: var(--mf-accent-glow);
+	--color-accent-dim: var(--mf-accent-dim);
 	--color-on-accent: var(--mf-on-art);
 	--color-scrim: var(--mf-scrim);
 	--color-on-art: var(--mf-on-art);
@@ -26,14 +28,15 @@
 	--color-danger-fg: oklch(88.5% 0.062 18.334);
 
 	--radius-control: 0.625rem;
-	--radius-panel: 1rem;
-	--radius-art: 0.75rem;
-	--radius-art-lg: 1rem;
+	--radius-panel: 1.125rem;
+	--radius-art: 0.85rem;
+	--radius-art-lg: 1.125rem;
 	--radius-art-round: 1.75rem;
 
 	--shadow-art: 0 12px 28px -10px rgba(0, 0, 0, 0.6);
-	--shadow-art-lg: 0 20px 45px -15px rgba(0, 0, 0, 0.7);
+	--shadow-art-lg: 0 24px 50px -16px rgba(0, 0, 0, 0.75);
 	--shadow-menu: 0 12px 28px -10px rgba(0, 0, 0, 0.6);
+	--shadow-glow: 0 0 0 1px var(--mf-border-strong), 0 20px 45px -20px var(--mf-accent-glow);
 }
 
 @utility page-x {
@@ -182,9 +185,24 @@ html {
 	overflow-x: hidden;
 }
 
-html.home {
-	background-image: linear-gradient(to bottom, var(--mf-accent), transparent 340px);
-	background-repeat: no-repeat;
+::selection {
+	background-color: var(--mf-accent-dim);
+	color: var(--mf-text);
+}
+
+body {
+	position: relative;
+}
+
+body::after {
+	content: '';
+	position: fixed;
+	inset: 0;
+	z-index: 80;
+	pointer-events: none;
+	opacity: 0.035;
+	mix-blend-mode: overlay;
+	background-image: var(--mf-noise);
 }
 
 ::-webkit-scrollbar {