feat(frontend): music player component with separated controls and stream proxy

frontend/src/routes/+layout.svelte

@@ -3,6 +3,8 @@
 	import favicon from '$lib/assets/favicon.svg';
 	import Navbar from '$lib/components/Navbar.svelte';
 	import Footer from '$lib/components/Footer.svelte';
+	import PlayerBar from '$lib/components/player/PlayerBar.svelte';
+	import { player } from '$lib/player/player.svelte';
 
 	let { children, data } = $props();
 </script>
@@ -13,4 +15,6 @@
 	<Navbar user={data.user} />
 	<main class="flex-1">{@render children()}</main>
 	<Footer />
+	<div class:pb-20={player.current}></div>
+	<PlayerBar />
 </div>

frontend/src/routes/api/tracks/[id]/stream/+server.ts

@@ -0,0 +1,20 @@
+import type { RequestHandler } from './$types';
+import { json, error } from '@sveltejs/kit';
+import { createApiClient } from '$lib/server/api';
+
+export const GET: RequestHandler = async ({ params, locals, fetch }) => {
+	if (!locals.accessToken) {
+		error(401, 'Inicia sesión para reproducir.');
+	}
+
+	const api = createApiClient({ fetch, accessToken: locals.accessToken });
+	const { data, error: err, response } = await api.GET('/tracks/{id}/stream', {
+		params: { path: { id: params.id } }
+	});
+
+	if (err || !data) {
+		error(response?.status ?? 502, 'No se pudo obtener el stream de la pista.');
+	}
+
+	return json(data);
+};