Added a new screenshot modal with options to copy, download, and choose image format. You can also set download as the default action. This version improves sidebar compatibility.

This update improves screenshot behavior and user feedback.

• Added clearer messaging when browser-protected pages cannot be captured.
• Disabled unsupported capture modes on PDF viewer pages while keeping visible-page capture available.
• Improved disabled button behavior so unavailable options no longer look interactive.
• Updated screenshot downloads to ask where to save the file.