feat(audio): upgrade rodio to 0.21 with waveform visualization

- Upgrade rodio dependency from 0.20 to 0.21
- Add real-time animated waveform visualization using BarChart widget
- Fix CLI/UI interference by disabling stream drop logging with log_on_drop(false)
- Update audio initialization to use OutputStreamBuilder::open_default_stream()
- Restore Sink::connect_new() API for sink creation
- Add terminal title display showing current playing song
- Implement 20-bar animated waveform with mathematical wave patterns
- Update UI layout to include dedicated waveform section
- Add .DS_Store to .gitignore to prevent future inclusion

BREAKING CHANGE: requires rodio 0.21+ for proper audio stream handling

Author: punk2049

.gitignore

@@ -1,4 +1,5 @@
 /target
 .claude
 *.mp3
-docs
+docs.DS_Store
+data/.DS_Store