Add Ctrl+Insert and Shift+Insert as copy/paste shortcuts

• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Is your feature request related to a problem? Please describe.
I would like diagrams.net / draw.io to support the conventional copy/paste shortcuts Ctrl+Insert and Shift+Insert.
I am left-handed, so I often use my right hand for keyboard shortcuts. Ctrl+Insert and Shift+Insert are more comfortable for my workflow than Ctrl+C and Ctrl+V.

Describe the solution you'd like
Please add support for these shortcuts on Windows/Linux:

• Ctrl+Insert = Copy
• Shift+Insert = Paste

Expected behavior:

1. Select a shape or text.
2. Press Ctrl+Insert to copy.
3. Press Shift+Insert to paste.
   (The result should be the same as using Ctrl+C and Ctrl+V.)

Describe alternatives you've considered
The current alternative is to use Ctrl+C and Ctrl+V, or the menu actions. These of course work, but they are less comfortable for my hand position.

Additional context
For context, I am on Windows and I tried these shortcuts in other browsers/apps, including DuckDuckGo Browser, Chrome, and Microsoft Edge. Ctrl+Insert and Shift+Insert work there as copy/paste shortcuts, so I expected similar behavior in app.diagrams.net.
These shortcuts are familiar to many Windows and Linux users, and they are useful for people with alternative keyboard workflows or accessibility needs.
I searched for existing issues mentioning Ctrl+Insert and Shift+Insert, but I could not find one for this specific shortcut request.

This issue may belong in the main draw.io / diagrams.net repository instead of drawio-desktop, since I am using the web version.
Thank You!

Start at the app.diagrams.net web editor and trace the existing JavaScript keyboard handling for Ctrl+C and Ctrl+V. Add equivalent Windows/Linux handling for Ctrl+Insert and Shift+Insert, then verify that selecting a shape or text produces the same copy and paste behavior.