Enhance String Button Animations

[pbalduino]

Description

Add subtle press animations to string selection buttons

Priority

🟢 Low

Category

UI Polish

Details

• Add press animation to string buttons in tuner_screen.dart
• Consider scale or elevation changes on tap
• Maintain existing selection highlighting
• Ensure animations don't interfere with selection feedback

Files Affected

• lib/screens/tuner_screen.dart

Acceptance Criteria

• String buttons show press feedback
• Animations are subtle and smooth
• Selection state remains clearly visible
• Performance is not impacted

Task ID: UI-003