debug: add secret check to health endpoint

app.py

@@ -88,4 +88,10 @@ async def cvat_webhook(request: Request):
 
 @app.get("/health")
 async def health():
-    return {"status": "ok", "dataset": DATASET}
+    return {
+        "status": "ok",
+        "dataset": DATASET,
+        "has_github_pat": bool(GITHUB_PAT),
+        "has_cvat_token": bool(CVAT_TOKEN),
+        "repo_ref": REPO_REF,
+    }