LLM planner, not perfect but ok

tools/create_invoice.py

@@ -0,0 +1,7 @@
+def create_invoice(args: dict) -> dict:
+    # e.g. amount, flight details, etc.
+    print("[CreateInvoice] Creating invoice with:", args)
+    return {
+        "invoiceStatus": "generated",
+        "invoiceURL": "https://pay.example.com/invoice/12345",
+    }