feat(cfold): canonicalize custom test layout

tests/hedgedoc/custom/test_health_check.py

@@ -0,0 +1,19 @@
+"""hedgedoc — health check: root path responds (200 or 302 to login/new).
+
+HedgeDoc may redirect / to /login or /new depending on auth config; either is healthy.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "..", "runner"))
+from harness import http as harness_http  # noqa: E402
+
+
+def test_hedgedoc_root_serves(live_app):
+    """GET / → 200 or 302 (login/new redirect)."""
+    url = f"https://{live_app}/"
+    status, _ = harness_http.retry_http_get(url, expect_status=(200, 302), max_wait=90, interval=5)
+    assert status in (200, 302), f"GET {url} HTTP {status} (expected 200 or 302)"