v0.0.4

What's new

• Music animations — floating notes on play, generate, and contribute flows
• Toolbar UI — glass-style toolbar with unified buttons API, replaces FAB
• Diff-aware contribute — toolbar indicator shows unsaved changes before contributing
• New songs — 秦海清 - 不如, 光良 - 童话 (edit), 林三七 - 野草与栀子花 (edit)

Fixes

• Community song timestamps now correct in all deploy environments — stored directly in song JSON instead of derived from git log