Fetch builds from Jenkins API

backend/app/services/builds.py

@@ -61,8 +61,7 @@ def fetch_builds(limit: int = 5) -> List[Dict]:
 
 def build_history() -> Dict:
     """Return Jenkins build history data."""
-    history = _load_json("build_history.json")
-    builds = history.get("builds", [])
+    builds = fetch_builds()
     return {
         "builds": [normalize_build(b) for b in builds]
     }