- Fix mouse coordinate scaling in piano roll when canvas is zoomed (getBoundingClientRect returns visual size, now dividing by scale ratio) - Replace Megaman melody with Super Mario Bros overworld theme - Tune chiptune preset: faster BPM (200), snappier envelopes, brighter filter, less delay/distortion for cleaner NES sound Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>