feat: 完善模型用量趋势与全局手账卡片并补齐阶段验收

backend/tests/test_usage_overrides.py

@@ -92,3 +92,25 @@ def test_real_adapter_body_and_usage_persistence():
     result = summary()
     assert result["request_count"] == 1 and result["totals"]["input_tokens"] == 10
     assert result["complete_requests"] == 1
+
+
+def test_usage_calendar_series_splits_sources_and_preserves_missing_counters():
+    start = datetime(2026, 9, 1, tzinfo=timezone.utc)
+    for source, hour, count in [('local', 15, 0), ('api', 16, 12), ('api', 17, None)]:
+        attempt = UsageAttempt('p', 'm', 'openai_compatible', source=source)
+        attempt.started_at = (start + timedelta(hours=hour)).isoformat()
+        if count is not None:
+            attempt.observe({'usage': {'input_tokens': count}})
+        attempt.persist()
+    result = aggregate(start, start + timedelta(days=2), timezone_offset=480)
+    assert result['series'][0]['local']['totals']['input_tokens'] == 0
+    second = result['series'][1]
+    assert second['date'] == '2026-09-02'
+    assert second['api']['requests'] == 2
+    assert second['api']['totals']['input_tokens'] == 12
+    assert second['api']['coverage']['input_tokens'] == 1
+    assert second['api']['totals']['output_tokens'] is None
+    assert sum(b['api']['requests'] + b['local']['requests'] for b in result['series']) == result['request_count']
+    filtered = aggregate(start, start + timedelta(days=2), source='local', timezone_offset=480)
+    assert all(b['api']['requests'] == 0 for b in filtered['series'])
+    assert len(aggregate(start, start + timedelta(days=3660))['series']) <= 90