Close [BS-3355](https://linear.app/affine-design/issue/BS-3355/白板快捷键c没有记住上次用的connector形状)
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## Summary by CodeRabbit
- **New Features**
- Added the ability to cycle through connector modes (Curve, Orthogonal, Straight) using the 'c' keyboard shortcut when the connector tool is active.
- **Bug Fixes**
- Improved the logic for remembering and restoring the last used connector mode when switching between tools.
- **Tests**
- Introduced a new end-to-end test to verify correct cycling and restoration of connector modes.
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