fix: restore default people-flow queue thresholds

managed/people_flow_project/src/people_flow/queue_analytics.py

@@ -92,7 +92,13 @@ class QueueWindowTracker:
                 self.closed_states.append(state)
                 del self.states[track_id]
 
-    def build_queue_metrics(self, window_start: datetime, window_end: datetime) -> dict:
+    def build_queue_metrics(
+        self,
+        window_start: datetime,
+        window_end: datetime,
+        *,
+        commit_queue_level: bool = True,
+    ) -> dict:
         totals: dict[int, int] = {}
         for state in self.closed_states:
             queue_seconds = state.window_queue_seconds(window_start, window_end)
@@ -120,7 +126,8 @@ class QueueWindowTracker:
         )
         previous_queue_level = self.last_queue_level
         status_change = _queue_status_change(previous_queue_level, queue_level)
-        self.last_queue_level = queue_level
+        if commit_queue_level:
+            self.last_queue_level = queue_level
         return {
             "queue_time_threshold_seconds": self.config.queue_time_threshold_seconds,
             "over_threshold_count": over_threshold_count,

managed/people_flow_project/tests/test_queue_analytics.py

@@ -46,3 +46,88 @@ def test_queue_window_tracker_builds_crowded_report():
     assert queue_metrics["previous_queue_level_label"] == ""
     assert queue_metrics["status_change"] == "initial"
     assert queue_metrics["status_change_label"] == "初始"
+
+
+def test_live_preview_does_not_overwrite_previous_finalized_queue_level():
+    tracker = QueueWindowTracker(
+        QueueConfig(
+            queue_time_threshold_seconds=60,
+            crowded_count_threshold=3,
+            normal_count_threshold=2,
+            pause_timeout_seconds=5,
+        ),
+        pixel_area=(0, 0, 100, 100),
+    )
+    first_window_start = datetime(2026, 4, 15, 11, 0, tzinfo=TZ)
+    first_window_end = datetime(2026, 4, 15, 11, 5, tzinfo=TZ)
+    second_window_start = first_window_end
+    second_window_preview = datetime(2026, 4, 15, 11, 7, tzinfo=TZ)
+    second_window_end = datetime(2026, 4, 15, 11, 10, tzinfo=TZ)
+
+    normal_tracks = [
+        TrackObservation(
+            track_id=index, bbox=(0, 0, 10, 10), confidence=0.9, center=(10, 10)
+        )
+        for index in range(1, 4)
+    ]
+    few_tracks = [
+        TrackObservation(
+            track_id=10, bbox=(0, 0, 10, 10), confidence=0.9, center=(10, 10)
+        )
+    ]
+
+    tracker.observe(normal_tracks, first_window_start)
+    tracker.observe(normal_tracks, first_window_end)
+    first_metrics = tracker.build_queue_metrics(first_window_start, first_window_end)
+
+    assert first_metrics["queue_level"] == "normal"
+    assert first_metrics["status_change"] == "initial"
+
+    tracker.reset()
+    tracker.observe(few_tracks, second_window_start)
+    tracker.observe([], second_window_preview)
+    preview_metrics = tracker.build_queue_metrics(
+        second_window_start,
+        second_window_preview,
+        commit_queue_level=False,
+    )
+
+    assert preview_metrics["queue_level"] == "few"
+    assert preview_metrics["previous_queue_level"] == "normal"
+    assert preview_metrics["status_change"] == "queue_decreased"
+
+    final_metrics = tracker.build_queue_metrics(second_window_start, second_window_end)
+
+    assert final_metrics["queue_level"] == "few"
+    assert final_metrics["previous_queue_level"] == "normal"
+    assert final_metrics["status_change"] == "queue_decreased"
+
+
+def test_queue_level_is_normal_when_count_reaches_threshold():
+    tracker = QueueWindowTracker(
+        QueueConfig(
+            queue_time_threshold_seconds=60,
+            crowded_count_threshold=3,
+            normal_count_threshold=2,
+            pause_timeout_seconds=5,
+        ),
+        pixel_area=(0, 0, 100, 100),
+    )
+    start = datetime(2026, 4, 15, 11, 0, tzinfo=TZ)
+    end = datetime(2026, 4, 15, 11, 5, tzinfo=TZ)
+    tracks = [
+        TrackObservation(
+            track_id=index, bbox=(0, 0, 10, 10), confidence=0.9, center=(10, 10)
+        )
+        for index in range(1, 4)
+    ]
+
+    tracker.observe(tracks, start)
+    tracker.observe(tracks, start.replace(minute=2))
+    tracker.observe([], end)
+
+    metrics = tracker.build_queue_metrics(start, end)
+
+    assert metrics["over_threshold_count"] == 3
+    assert metrics["queue_level"] == "normal"
+    assert metrics["queue_level_label"] == "人数正常"