feat: Add mouse gesture feature

[xtxo]

Summary

This PR adds a mouse gesture feature to Mos, allowing users to trigger keyboard shortcuts by holding the right mouse button and moving in specific directions.

Motivation / Why This Feature

使用场景：

很多用户习惯用鼠标右键长按来触发 ESC 键（比如关闭弹窗、退出全屏、取消操作等）。但现有的 Mos 功能只能绑定单个按键，无法实现"按住右键 + 移动方向"这种更直观的手势操作。

痛点：

1. 长按右键触发 ESC 需要一直按着，手指容易疲劳
2. 无法同时触发多个快捷键（比如 ESC 和刷新）
3. 没有方向感，操作不够直觉

解决方案：
通过鼠标手势，用户可以：

• 按住右键 → 向左上方移动 → 触发 ESC（退出/取消）
• 按住右键 → 向上移动 → 触发 Cmd+R（刷新页面）

这样更符合直觉，也更高效。未来可以扩展更多方向和功能。

Changes

• New file: Mos/ButtonCore/MouseGestureTracker.swift - Core gesture tracking logic
• Modified: Mos/ButtonCore/ButtonCore.swift - Integration with existing event tap system

Feature Details

How it works

1. Hold the right mouse button
2. Move the mouse in a direction (minimum 30px distance)
3. Release the right button

Default gestures

Direction	Action	Use Case
Up-Left (↖)	ESC key	关闭弹窗、退出全屏、取消操作
Up (↑)	Cmd+R	刷新页面、重新加载

Technical implementation

• Uses CGEventTap to monitor mouse movement while right button is held
• Calculates direction based on movement angle
• Supports 8 directions (up, down, left, right, and 4 diagonals)
• Minimum distance threshold prevents accidental triggers
• Integrates with existing ButtonCore and InputProcessor architecture

Testing

• Verified gesture tracking starts on right mouse down
• Verified gesture tracking stops on right mouse up
• Verified ESC key is triggered for up-left direction
• Verified Cmd+R is triggered for up direction
• Verified minimum distance threshold works correctly

Notes

This is a basic implementation. Future enhancements could include:

• User-configurable gesture directions and actions
• More gesture directions (down, left, right, diagonals)
• Visual feedback during gesture recognition
• Gesture recording UI
• Support for other mouse buttons (middle, back, forward)