Fix training agent heartbeat status

tests/test_training_coordination.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import base64
 import hashlib
+import json
 
 from crypto_spot_bot.training_coordination import TrainingCoordinator
 
@@ -68,3 +69,20 @@ def test_training_coordinator_accepts_chunked_artifact_upload(tmp_path) -> None:
     assert part_2["complete"] is True
     assert (tmp_path / "lstm_forecaster.json").read_bytes() == payload
     assert coordinator.status()["latest_job"]["artifacts"][0]["sha256"] == sha256
+
+
+def test_running_claimed_job_keeps_agent_online_when_heartbeat_is_stale(tmp_path) -> None:
+    coordinator = TrainingCoordinator(tmp_path)
+    coordinator.request_retrain({"source": "android"})
+    coordinator.claim({"worker_id": "win-1", "name": "DESKTOP-TMFDL0H"})
+
+    state_path = tmp_path / "training_coordination.json"
+    state = json.loads(state_path.read_text(encoding="utf-8"))
+    state["worker"]["last_seen_at"] = "2026-01-01T00:00:00+00:00"
+    state_path.write_text(json.dumps(state), encoding="utf-8")
+
+    status = coordinator.status()
+
+    assert status["agent_recently_seen"] is False
+    assert status["agent_busy"] is True
+    assert status["agent_online"] is True