Add setting to customize how the Enter key behaves in prompt input field

[Alek2077]

Add an option in the settings (or in a visible, easily accessible place) to switch between:

Enter = newline / Shift+Enter or Ctrl+Enter = send

Enter = send / Shift+Enter = newline (current default)

This flexibility improves ergonomics for users who write long or structured prompts and want faster multiline input without holding modifier keys. Those of us typing hundreds of words per prompt find it physically tiring to hold Shift constantly, and we occasionally send prompts by mistake when we forget.
Google AI Studio does this by default.

Why it matters:

• Reduces finger fatigue from constantly holding Shift
• Prevents accidental prompt submissions due to missed Shift
• Aligns with common editors and markdown interfaces
• Improves usability for power users writing structured input manually

[nikhil-swamix]

also add current file in context like how continue.dev does would be good?
alt+enter = add current file and send (instructs to only work with current open file, and no searching relevant files across codebase!)