feat(cfold): canonicalize custom test layout

tests/bluesky-pds/custom/test_health_check.py

@@ -0,0 +1,22 @@
+"""bluesky-pds — Phase-2 health_check (recipe-maintainer corpus has no health_check.py).
+
+Tests the PDS's `/xrpc/_health` endpoint; asserts 200 + JSON with a `version` field.
+"""
+
+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_pds_health_returns_version(live_app):
+    """GET /xrpc/_health → 200, JSON {"version": "..."}."""
+    url = f"https://{live_app}/xrpc/_health"
+    status, body = harness_http.retry_http_get(url, expect_status=200, max_wait=60, interval=3)
+    assert status == 200, f"GET {url} HTTP {status} (expected 200)"
+    assert (
+        isinstance(body, dict) and isinstance(body.get("version"), str) and body["version"]
+    ), f"GET {url} response is not the expected health envelope: {body!r}"