- Add VisibilityChangeModal for confirming visibility changes
- Add VisibilityChangeManager to handle events and drag detection
- GoogleItem shapes now dispatch visibility change events on badge click
- Support both local->shared and shared->local transitions
- Auto-detect when GoogleItems are dragged outside PrivateWorkspace
- Session storage for "don't ask again" preference
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
