[BUG] Shift+Ctrl+C with no selection falls through to Ctrl+C clear/exit behavior

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When no text is selected, Shift+Ctrl+C falls through to Ctrl+C behavior (clears input, double-press exits). I expect a no-op instead.

Current behavior:

• text selected + Shift+Ctrl+C → copies text ✓
• no selection + Shift+Ctrl+C → clears input / exits on double-press ✗

Why this is a problem:

• Shift+Ctrl+V pastes, and Shift+Ctrl+C is one key away — easy to mis-hit while pasting, and unrecoverably deletes the input contents
• holding shift is a meaningfully different intent, and it's surprising that it's not taken into account (destructively too!)

What Should Happen?

No-op — pressing Shift+Ctrl+C with no selection should do nothing (or visual feedback like "nothing to copy"), not fall through to Ctrl+C behavior.

Steps to Reproduce

1. type some text in the input field (don't submit)
2. press Shift+Ctrl+C (with no text selected)
3. result: input is cleared, same as Ctrl+C
4. expected: no-op (nothing happens)

Contrast — correct behavior when text is selected:

1. type some text in the input field
2. select some of the text
3. press Shift+Ctrl+C
4. result: text is copied ✓

This shows the shift modifier is already detected; only the no-selection fallback is incorrect.

Is this a regression?

No, this never worked

Claude Code Version

2.1.2

Operating System

Other Linux

Terminal/Shell

Other