feat(v1): add local alerts, screenshot and JSONL event log

AlertDispatcher de-duplicates by event_id and fires each side effect once
per CONFIRMED: annotated screenshot, one JSONL line (config_version,
source_id, no rtsp/credentials), sound and popup via injectable sink.
44 tests pass; real-frame artifact smoke verified.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

v1/tests/test_alerts.py

@@ -0,0 +1,123 @@
+import json
+from datetime import datetime, timezone
+
+import numpy as np
+import pytest
+
+from v1.alerts import AlertDispatcher, AlertSink, EventArtifactWriter, annotate_frame
+from v1.fall_state import FallEvent, FallState
+from v1.view_model import MonitorViewState, PersonOverlay, Point, StatusColor
+
+
+class RecordingSink(AlertSink):
+    def __init__(self):
+        self.sounds = []
+        self.popups = []
+
+    def play_sound(self, event):
+        self.sounds.append(event.event_id)
+
+    def show_popup(self, record):
+        self.popups.append(record.event.event_id)
+
+
+def _event(event_id="FALL-000001", track_id="P-0003"):
+    return FallEvent(
+        event_id=event_id,
+        track_id=track_id,
+        config_version="cfg-abc123",
+        suspected_at_monotonic=0.0,
+        confirmed_at_monotonic=1.8,
+        latency_seconds=1.8,
+    )
+
+
+def _confirmed_view():
+    overlay = PersonOverlay(
+        track_id="P-0003",
+        state=FallState.CONFIRMED,
+        color=StatusColor.CRITICAL,
+        box_xyxy=(20.0, 20.0, 80.0, 180.0),
+        keypoints=(Point(30.0, 40.0), Point(40.0, 40.0)),
+        skeleton_segments=((Point(30.0, 40.0), Point(40.0, 40.0)),),
+        label="P-0003 · CONFIRMED",
+    )
+    return MonitorViewState(
+        connected=True,
+        status_text="在线",
+        status_color=StatusColor.SUCCESS,
+        has_frame=True,
+        people=(overlay,),
+        events=(),
+        highest_state=FallState.CONFIRMED,
+    )
+
+
+def _writer(tmp_path):
+    fixed = datetime(2026, 7, 21, 8, 30, 0, tzinfo=timezone.utc)
+    return EventArtifactWriter(tmp_path, source_id="lobby-camera-01", clock=lambda: fixed)
+
+
+def _image():
+    return np.full((200, 240, 3), 30, dtype=np.uint8)
+
+
+def test_confirmed_event_fires_each_side_effect_once(tmp_path):
+    sink = RecordingSink()
+    dispatcher = AlertDispatcher(_writer(tmp_path), sink)
+    event = _event()
+
+    first = dispatcher.dispatch([event], _image(), _confirmed_view())
+    second = dispatcher.dispatch([event], _image(), _confirmed_view())
+
+    assert len(first) == 1
+    assert second == ()
+    assert sink.sounds == ["FALL-000001"]
+    assert sink.popups == ["FALL-000001"]
+    log_path = tmp_path / "20260721" / "events.jsonl"
+    assert log_path.read_text(encoding="utf-8").count("\n") == 1
+    assert (tmp_path / "20260721" / "FALL-000001.png").is_file()
+
+
+def test_jsonl_record_has_fields_and_no_source_address(tmp_path):
+    dispatcher = AlertDispatcher(_writer(tmp_path))
+    dispatcher.dispatch([_event()], _image(), _confirmed_view())
+
+    line = (tmp_path / "20260721" / "events.jsonl").read_text(encoding="utf-8").strip()
+    record = json.loads(line)
+    assert record["event_id"] == "FALL-000001"
+    assert record["config_version"] == "cfg-abc123"
+    assert record["source_id"] == "lobby-camera-01"
+    assert record["state"] == "CONFIRMED"
+    assert record["confirmed_at_utc"] == "2026-07-21T08:30:00+00:00"
+    assert record["screenshot"] == "20260721/FALL-000001.png"
+    assert "rtsp" not in line.lower()
+    assert "password" not in line.lower()
+
+
+def test_missing_image_produces_no_side_effect(tmp_path):
+    sink = RecordingSink()
+    dispatcher = AlertDispatcher(_writer(tmp_path), sink)
+
+    records = dispatcher.dispatch([_event()], None, _confirmed_view())
+
+    assert records == ()
+    assert sink.sounds == []
+    assert not (tmp_path / "20260721").exists()
+
+
+def test_distinct_events_produce_two_log_lines(tmp_path):
+    dispatcher = AlertDispatcher(_writer(tmp_path))
+    dispatcher.dispatch([_event("FALL-000001")], _image(), _confirmed_view())
+    dispatcher.dispatch([_event("FALL-000002", "P-0009")], _image(), _confirmed_view())
+
+    lines = (tmp_path / "20260721" / "events.jsonl").read_text(encoding="utf-8").strip().split("\n")
+    assert len(lines) == 2
+
+
+def test_annotate_draws_red_border_only_for_confirmed():
+    image = np.full((60, 80, 3), 30, dtype=np.uint8)
+    confirmed = annotate_frame(image, _confirmed_view())
+    corner = confirmed[0, 0].tolist()
+    assert corner == [40, 40, 198]  # critical red in BGR
+    assert confirmed.shape == image.shape