feat: improve cloud sync reliability and background status

tests/test_mi_fitness_cloud.py

@@ -1,6 +1,9 @@
 import pytest
 
-from mi_fitness_mcp.adapters.mi_fitness_cloud import MiFitnessCloudAdapter
+from mi_fitness_mcp.adapters.mi_fitness_cloud import (
+    MiFitnessCloudAdapter,
+    _is_authentication_error,
+)
 
 
 async def _collect(async_iterable):
@@ -29,6 +32,7 @@ def test_record_datetime_uses_zone_offset():
     dt = adapter._record_datetime({"time": 0, "zone_offset": 10800})
     assert dt.isoformat().startswith("1970-01-01T03:00:00")
 
+
 @pytest.mark.asyncio
 async def test_iter_daily_activity_aggregates_steps_and_calories(monkeypatch):
     adapter = MiFitnessCloudAdapter(user_id="u1", pass_token="p1")
@@ -63,3 +67,36 @@ async def test_iter_daily_activity_aggregates_steps_and_calories(monkeypatch):
     assert items[0].steps == 30
     assert items[0].distance_m == 24
     assert items[0].active_kcal == 12
+
+
+@pytest.mark.asyncio
+async def test_fetch_key_rejects_repeated_pagination_cursor(monkeypatch):
+    adapter = MiFitnessCloudAdapter(user_id="u1", pass_token="p1", region="cn")
+    adapter._client = object()
+
+    async def fake_request(base_url, api_path, payload):
+        return {"data_list": [], "has_more": True, "next_key": "same"}
+
+    monkeypatch.setattr(adapter, "_request", fake_request)
+    with pytest.raises(RuntimeError, match="cursor loop"):
+        await adapter._fetch_key("steps", "2026-07-06", "2026-07-12")
+
+
+@pytest.mark.asyncio
+async def test_connect_failure_closes_client(monkeypatch):
+    adapter = MiFitnessCloudAdapter(user_id="u1", pass_token="bad", region="cn")
+
+    async def failed_login(user_id, pass_token):
+        raise RuntimeError("invalid credentials")
+
+    monkeypatch.setattr(adapter, "_login_with_token", failed_login)
+    assert await adapter.connect() is False
+    assert adapter._client is None
+    assert "invalid credentials" in adapter.last_error
+
+
+def test_authentication_error_detection():
+    assert _is_authentication_error(401, "denied")
+    assert _is_authentication_error(0, "session expired")
+    assert _is_authentication_error(-10001, "unknown")
+    assert not _is_authentication_error(500, "temporary server failure")