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/tests/unit_tests/services/test_challenge_service.py

@@ -37,4 +37,3 @@ def test_record_attempt_creates_row(mocker):
     assert isinstance(attempt, ChallengeAttempt)
     session.add.assert_called_once()
     session.commit.assert_called_once()
-

api/tests/unit_tests/services/test_red_blue_service.py

@@ -24,11 +24,7 @@ def test_submit_prompt_creates_submission(mocker):
 def test_select_counterparty_submission_latest_active(mocker):
     c = SimpleNamespace(id="cid")
     session = mocker.MagicMock()
-    qs = (
-        session.query.return_value.filter.return_value.order_by.return_value
-    )
+    qs = session.query.return_value.filter.return_value.order_by.return_value
     qs.first.return_value = SimpleNamespace(id="subid", team="blue")
     sub = RedBlueService.select_counterparty_submission(challenge=c, team="red", session=session)
     assert sub.team == "blue"
-
-