fix: remove invalid prompt_toolkit ctrl-shift-c binding

cli.py

@@ -10484,21 +10484,6 @@ def handle_ctrl_c(event):
                     self._should_exit = True
                     event.app.exit()
 
-        @kb.add('c-S-c')  # Ctrl+Shift+C
-        def handle_ctrl_shift_c(event):
-            """Copy text to clipboard (terminal-native).
-
-            This is a no-op at the application level. Terminal emulators
-            handle the actual copy operation when Ctrl+Shift+C is pressed.
-            This binding prevents Hermes from intercepting the keystroke
-            as an interrupt signal.
-
-            On macOS the standard copy shortcut is Cmd+C (no Hermes binding
-            needed). On Linux/Windows Ctrl+Shift+C is the conventional
-            terminal copy shortcut.
-            """
-            return  # No-op — let the terminal perform native copy
-
         @kb.add('c-q')  # Ctrl+Q
         def handle_ctrl_q(event):
             """Alternative interrupt/exit shortcut (Ctrl+Q).

tests/hermes_cli/test_cli_keybindings.py

@@ -0,0 +1,53 @@
+"""Regression tests for prompt_toolkit CLI key bindings."""
+
+import ast
+from pathlib import Path
+
+import pytest
+from prompt_toolkit.key_binding import KeyBindings
+
+
+CLI_PATH = Path(__file__).resolve().parents[2] / "cli.py"
+
+
+def _literal_key_sequences_from_cli():
+    """Return literal key sequences passed to ``*.add(...)`` in cli.py.
+
+    prompt_toolkit validates key names when decorators are registered. A bad
+    key name in the interactive CLI prevents ``hermes`` from starting, so keep
+    this lightweight static regression test around for startup safety.
+    """
+    tree = ast.parse(CLI_PATH.read_text(), filename=str(CLI_PATH))
+    sequences = []
+
+    for node in ast.walk(tree):
+        if not isinstance(node, ast.Call):
+            continue
+        if not isinstance(node.func, ast.Attribute) or node.func.attr != "add":
+            continue
+        if not isinstance(node.func.value, ast.Name) or node.func.value.id != "kb":
+            continue
+
+        literal_keys = []
+        for arg in node.args:
+            if isinstance(arg, ast.Constant) and isinstance(arg.value, str):
+                literal_keys.append(arg.value)
+            else:
+                # Dynamic bindings such as kb.add(str(_num), ...) are covered
+                # by runtime tests; this check is for hard-coded key names.
+                literal_keys = []
+                break
+        if literal_keys:
+            sequences.append(tuple(literal_keys))
+
+    return sequences
+
+
+@pytest.mark.parametrize("keys", _literal_key_sequences_from_cli())
+def test_cli_literal_keybindings_are_valid_prompt_toolkit_keys(keys):
+    """Every hard-coded key binding in cli.py must be accepted by prompt_toolkit."""
+    kb = KeyBindings()
+
+    @kb.add(*keys)
+    def _handler(event):  # pragma: no cover - registration is the assertion
+        return None