Add multi-site Caddy helpers and document usage

- add startup/shutdown scripts that render a Caddyfile from JSON config and run health checks

- add Python utilities and a sample sites.json for declarative multi-site configuration

- document the workflow and ignore generated Caddy state artifacts

- normalize double-quote style across challenge workflow controllers, nodes, and tests

api/controllers/web/red_blue_challenges.py

@@ -82,4 +82,3 @@ class RedBlueLeaderboardApi(Resource):
             "blue_ratio": (float(blue or 0.0) / total) if total else 0.0,
         }
         return {"result": "success", "data": data}
-