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

frontend/src/lib/components/player/SeekBar.svelte

@@ -0,0 +1,26 @@
+<script lang="ts">
+	import { player } from '$lib/player/player.svelte';
+
+	function format(seconds: number) {
+		if (!Number.isFinite(seconds) || seconds < 0) return '0:00';
+		const minutes = Math.floor(seconds / 60);
+		const rest = Math.floor(seconds % 60);
+		return `${minutes}:${rest.toString().padStart(2, '0')}`;
+	}
+</script>
+
+<div class="flex w-full items-center gap-2">
+	<span class="w-10 text-right text-xs tabular-nums text-neutral-500">{format(player.currentTime)}</span>
+	<input
+		type="range"
+		min="0"
+		max={player.duration || 0}
+		step="0.1"
+		value={player.currentTime}
+		disabled={!player.duration}
+		oninput={(event) => player.seek(Number(event.currentTarget.value))}
+		aria-label="Progreso"
+		class="h-1 w-full cursor-pointer accent-emerald-500"
+	/>
+	<span class="w-10 text-xs tabular-nums text-neutral-500">{format(player.duration)}</span>
+</div>