feat: add get_vlans, get_gateway_interfaces tools and billing config fallback

- Add get_vlans tool to filter interfaces by type=vlan
- Add get_gateway_interfaces tool to identify gateway interfaces from routes
- Add fallback to billing-mcp/config.json when router not in devices.json
- Update .gitignore to exclude venv, pycache, snapshots

json_to_csv.py

@@ -0,0 +1,42 @@
+
+import json
+import csv
+import sys
+
+def json_to_csv(json_file_path, csv_file_path):
+    """
+    Converts a JSON file containing a list of objects to a CSV file.
+    """
+    try:
+        with open(json_file_path, 'r') as f:
+            data = json.load(f)
+
+        if not isinstance(data, list) or not data:
+            print("Error: JSON file should contain a non-empty list of objects.")
+            return
+
+        # Get all unique headers from all objects in the list
+        headers = set()
+        for item in data:
+            headers.update(item.keys())
+        headers = sorted(list(headers))
+
+        with open(csv_file_path, 'w', newline='') as f:
+            writer = csv.DictWriter(f, fieldnames=headers)
+            writer.writeheader()
+            writer.writerows(data)
+
+        print(f"Successfully converted {json_file_path} to {csv_file_path}")
+
+    except FileNotFoundError:
+        print(f"Error: The file {json_file_path} was not found.")
+    except json.JSONDecodeError:
+        print(f"Error: Could not decode JSON from the file {json_file_path}.")
+    except Exception as e:
+        print(f"An unexpected error occurred: {e}")
+
+if __name__ == "__main__":
+    if len(sys.argv) != 3:
+        print("Usage: python json_to_csv.py <input_json_file> <output_csv_file>")
+    else:
+        json_to_csv(sys.argv[1], sys.argv[2])