Some Keyboard Shortcuts

- [ ] `CTRL+A `= Copy Bitmap Area
- [ ] `CTRL+C `= Copy bitmap area
- [ ] `CTRL+V` = Paste bitmap area
- [x] `CTRL+S` = Save image
- [ ] `CTRL+Z` = Undo
- [ ] `CTRL+Y` = Redo
- [x] `CTRL+N` = Open new page
- [x] `CTRL+G` = Toggle gridline
- [x] `CTRL+E` = Open settings page
- [x] `CTRL+P` = Open print dialog page
- [x] `CTRL+R` = Toggle ruler
- [x] `CTRL+ Num +` = Increase size
- [x] `CTRL + Num -` = Descrease size

The issue lists keyboard shortcuts to implement in a WinForms paint application. Look for the main form or key event handlers in the codebase. Check existing shortcuts like CTRL+S to understand the pattern. Implement the missing shortcuts by adding event handlers for key combinations and connecting them to the appropriate actions (copy, paste, undo, redo). Test by running the application and verifying the shortcuts work.

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