v0.4

Add activity-level app selection and git-synced version display

- Implement long-press to show activity selection dialog for each app
- Add ActivityHelper to discover all launchable activities in an app
- Create ActivitySelectionDialog with clean UI for activity selection
- Support launching specific activities instead of just default launcher
- Add fallback mechanism if specific activity launch fails
- Sync version number display with git tags in toolbar
- Fix version display to avoid duplicate 'v' prefix

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Co-Authored-By: Claude <noreply@anthropic.com>