feat(F1): integrate Web Push notifications into event processor

Import send_alert into processor.py, store engine as self._engine after
init_db(), extend _execute_action() to accept event_type/severity/source_id
and call send_alert for alert_all and push_and_record actions, and pass
those params from _handle_event().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit/test_processor_alerts.py

@@ -0,0 +1,35 @@
+"""Test that event processor calls send_alert for alert actions."""
+
+from unittest.mock import MagicMock, patch
+
+from vigilar.config import VigilarConfig
+from vigilar.events.processor import EventProcessor
+
+
+def test_execute_action_calls_send_alert():
+    cfg = VigilarConfig()
+    processor = EventProcessor(cfg)
+    processor._engine = MagicMock()
+    mock_bus = MagicMock()
+
+    with patch("vigilar.events.processor.send_alert") as mock_send:
+        processor._execute_action(
+            action="alert_all", event_id=42, bus=mock_bus,
+            payload={"species": "bear"},
+            event_type="WILDLIFE_PREDATOR", severity="CRITICAL", source_id="front",
+        )
+        mock_send.assert_called_once()
+
+
+def test_execute_action_push_and_record():
+    cfg = VigilarConfig()
+    processor = EventProcessor(cfg)
+    processor._engine = MagicMock()
+    mock_bus = MagicMock()
+
+    with patch("vigilar.events.processor.send_alert") as mock_send:
+        processor._execute_action(
+            action="push_and_record", event_id=10, bus=mock_bus,
+            payload={}, event_type="PERSON_DETECTED", severity="WARNING", source_id="cam1",
+        )
+        mock_send.assert_called_once()