Smart Ctrl+C: copy on selection, double-tap for SIGINT

Single Ctrl+C with selection → copies text to clipboard.
Single Ctrl+C without selection → sends SIGINT.
Double Ctrl+C (within 300ms) → always sends SIGINT.
Protects against accidentally killing programs when trying to copy.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gui/widgets/terminal_widget.py

@@ -6,6 +6,7 @@ DECCKM, bracketed paste, mouse tracking, and professional copy/paste UX.
 
 import codecs
 import copy
+import time
 import tkinter as tk
 import tkinter.font as tkfont
 import pyte
@@ -209,6 +210,7 @@ class TerminalWidget(tk.Frame):
 
         # ── Selection tracking for copy ──
         self._selecting = False
+        self._last_ctrl_c: float = 0.0
 
         # ── Status bar ──
         self._status_frame = tk.Frame(self, bg="#2d2d44", height=22)
@@ -519,6 +521,27 @@ class TerminalWidget(tk.Frame):
     def _on_ctrl_c(self, event):
         if event.state & 0x1:  # Shift held → Ctrl+Shift+C → copy
             return self._on_copy(event)
+
+        now = time.monotonic()
+        double = (now - self._last_ctrl_c) < 0.3
+        self._last_ctrl_c = now
+
+        if double:
+            # Double Ctrl+C → always SIGINT (force kill)
+            self._send(b"\x03")
+            return "break"
+
+        # Single Ctrl+C: copy if there is a selection, otherwise SIGINT
+        try:
+            sel = self._text.get("sel.first", "sel.last")
+            if sel:
+                self.clipboard_clear()
+                self.clipboard_append(sel)
+                return "break"
+        except tk.TclError:
+            pass
+
+        # No selection → SIGINT
         self._send(b"\x03")
         return "break"