chore: import upstream snapshot with attribution

showcase/integrations/langgraph-python/tools/schedule_meeting.py

@@ -0,0 +1,31 @@
+"""Schedule meeting tool implementation.
+
+The HITL gating happens on the frontend via useHumanInTheLoop.
+This tool just returns a pending approval status for the framework
+wrapper to surface.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+
+def schedule_meeting_impl(
+    reason: str,
+    duration_minutes: int = 30,
+) -> dict[str, Any]:
+    """Schedule a meeting (requires human approval).
+
+    Returns a pending_approval status. The actual gating is done by the
+    frontend's useHumanInTheLoop hook — the agent pauses until the user
+    approves or rejects.
+    """
+    return {
+        "status": "pending_approval",
+        "reason": reason,
+        "duration_minutes": duration_minutes,
+        "message": (
+            f"Meeting request: {reason} ({duration_minutes} min). "
+            "Awaiting human approval."
+        ),
+    }