feat: Add database migrations and auth system

- Add Alembic for database migrations
- Implement user authentication system
- Update frontend styles and components
- Add new test audio functionality
- Update stream management and UI

public_streams.txt

@@ -1 +1,3 @@
 {"uid":"devuser","size":22455090,"mtime":1747563720}
+{"uid":"oib9","size":2019706,"mtime":1751124547}
+{"uid":"orangeicebear","size":1734396,"mtime":1748767975}