fix 500

backend/app/lifespan.py

@@ -54,6 +54,22 @@ async def lifespan(app: FastAPI):
     set_pg_pool(pg_pool)
     app.state.pg_pool = pg_pool
 
+    # Fail fast if Flyway routines are missing (otherwise heartbeat silently goes stale in FE).
+    async with pg_pool.acquire() as conn:
+        fn_ok = await conn.fetchval(
+            """
+            select exists(
+              select 1
+              from pg_proc p
+              join pg_namespace n on n.oid = p.pronamespace
+              where n.nspname = 'ems'
+                and p.proname = 'fn_update_heartbeat'
+            )
+            """
+        )
+        if not fn_ok:
+            raise RuntimeError("Missing DB routine: ems.fn_update_heartbeat")
+
     app.state.ws_log_handler = WSLogHandler()
     app.state.ws_log_handler.setLevel(logging.INFO)
     logging.getLogger().addHandler(app.state.ws_log_handler)

backend/app/routers/full_status.py

@@ -126,9 +126,9 @@ async def get_site_status_full(
     tomorrow_slots = int(bundle.get("tomorrow_price_slot_count") or 0)
 
     now_utc = datetime.now(timezone.utc)
-    hb_last = hb_row.get("last_seen") if hb_row else None
+    hb_last = _parse_ts(hb_row.get("last_seen") if hb_row else None)
     hb_age = _age_seconds(hb_last)
-    inv_measured = inv_row.get("measured_at") if inv_row else None
+    inv_measured = _parse_ts(inv_row.get("measured_at") if inv_row else None)
     inv_age = _age_seconds(inv_measured)
 
     next_start, next_bat = _next_plan_interval(intervals, now_utc)

backend/services/heartbeat_service.py

@@ -61,7 +61,7 @@ async def send_heartbeat(
 
         status = "ok" if (not endpoint or loxone_ok) else "degraded"
         await db.execute(
-            "SELECT ems.fn_update_heartbeat($1, $2, $3)",
+            "select ems.fn_update_heartbeat($1, $2, $3)",
             site_id,
             status,
             EMS_BACKEND_VERSION,

backend/tests/test_full_status_heartbeat_parsing.py

@@ -0,0 +1,53 @@
+import asyncio
+
+
+class _FakeAcquire:
+    def __init__(self, conn):
+        self._conn = conn
+
+    async def __aenter__(self):
+        return self._conn
+
+    async def __aexit__(self, exc_type, exc, tb):
+        return False
+
+
+class _FakePool:
+    def __init__(self, conn):
+        self._conn = conn
+
+    def acquire(self):
+        return _FakeAcquire(self._conn)
+
+
+def test_status_full_parses_heartbeat_and_inverter_timestamps(monkeypatch):
+    # Regression: /status/full used to pass string timestamps into _age_seconds()
+    # which expects datetime and accesses .tzinfo.
+    from app.routers import full_status
+
+    async def _fake_fetch_json(conn, sql, *args):
+        assert "fn_site_full_status" in sql
+        return {
+            "site": {"code": "X"},
+            "operating_mode": {"mode_code": "AUTO"},
+            "heartbeat": {"last_seen": "2026-04-20T08:56:36.186Z"},
+            "inverter_latest": {"measured_at": "2026-04-20T08:56:31.165Z"},
+            "ev_chargers": [],
+            "heat_pump_latest": None,
+            "battery_limits": {},
+            "active_plan": None,
+            "planning_intervals": [],
+            "tomorrow_price_slot_count": 96,
+        }
+
+    monkeypatch.setattr(full_status, "fetch_json", _fake_fetch_json)
+
+    out = asyncio.run(
+        full_status.get_site_status_full(site_id=2, pool=_FakePool(conn=object()))
+    )
+    assert isinstance(out, dict)
+    assert out["heartbeat"]["last_seen"] is not None
+    assert out["heartbeat"]["age_seconds"] is not None
+    assert out["telemetry"]["inverter"]["measured_at"] is not None
+    assert out["telemetry"]["inverter"]["age_seconds"] is not None
+