Cache music as mp3 files on startup

src/lib/music/player.svelte.ts

@@ -14,6 +14,8 @@ class MusicPlayer {
 	history = $state<number[]>([]);
 	repeat = $state(false);
 
+	audioElement: HTMLAudioElement | null = null;
+
 	private failedTrackCount = 0;
 	private loading = false;
 
@@ -108,7 +110,13 @@ class MusicPlayer {
 	}
 
 	seek(seconds: number) {
-		this.startOffset = Math.max(0, Math.min(Math.floor(seconds), this.duration - 1));
+		const targetSeconds = Math.max(0, Math.min(Math.floor(seconds), this.duration - 1));
+		if (this.currentTrack?.cached && this.audioElement) {
+			this.audioElement.currentTime = targetSeconds;
+			this.paused = false;
+			return;
+		}
+		this.startOffset = targetSeconds;
 		this.elapsedSinceStart = 0;
 		this.streamKey += 1;
 		this.paused = false;