fix: use user log stat endpoint for finance upstream costs

backend/test_finance_daily_summary.py

@@ -282,7 +282,7 @@ def test_upstream_cost_new_api_success(monkeypatch):
     assert err is None
     assert abs(amount - 10.0) < 1e-6  # 5_000_000 / 500_000 = 10.0
     assert mock_client_instance.calls[0]["method"] == "GET"
-    assert mock_client_instance.calls[0]["url"] == "http://up.test/api/log/stat"
+    assert mock_client_instance.calls[0]["url"] == "http://up.test/api/log/self/stat"
     assert mock_client_instance.calls[0]["params"] == {
         "type": 2,
         "start_timestamp": 1782921600,
@@ -290,6 +290,33 @@ def test_upstream_cost_new_api_success(monkeypatch):
     }
 
 
+def test_upstream_cost_new_api_zero_quota_success(monkeypatch):
+    u = FakeUpstream(api_prefix="", auth_type="new_api_token")
+    monkeypatch.setattr(
+        "app.services.finance_service.UpstreamClient",
+        lambda **kw: FakeUpstreamClientCtx(response={"data": {"quota": 0}}),
+    )
+
+    amount, err = fetch_upstream_cost_new_api(u, date(2026, 7, 2))
+
+    assert err is None
+    assert amount == 0.0
+
+
+def test_upstream_cost_new_api_success_false_uses_remote_message(monkeypatch):
+    u = FakeUpstream(api_prefix="", auth_type="new_api_token")
+    monkeypatch.setattr(
+        "app.services.finance_service.UpstreamClient",
+        lambda **kw: FakeUpstreamClientCtx(response={"success": False, "message": "无权访问日志统计"}),
+    )
+
+    amount, err = fetch_upstream_cost_new_api(u, date(2026, 7, 2))
+
+    assert amount == 0.0
+    assert err == "无权访问日志统计"
+    assert "quota" not in err
+
+
 def test_upstream_cost_new_api_missing_quota(monkeypatch):
     u = FakeUpstream(api_prefix="", auth_type="new_api_token")
     monkeypatch.setattr(