feat(mcp_client): add MUTATING_TOOLS frozenset sentinel for HITL enforcement

mcp_client.py

@@ -40,6 +40,17 @@ import urllib.parse
 from html.parser import HTMLParser
 import re as _re
 
+# ------------------------------------------------------------------ mutating tools sentinel
+
+# Tools that write or modify files. ai_client checks this set before dispatch
+# and routes to pre_tool_callback (GUI approval) if the tool name is present.
+MUTATING_TOOLS: frozenset[str] = frozenset({
+ "set_file_slice",
+ "py_update_definition",
+ "py_set_signature",
+ "py_set_var_declaration",
+})
+
 # ------------------------------------------------------------------ state
 
 # Set by configure() before the AI send loop starts.