feat: add audit events and runtime state snapshots to database

- Introduced new tables for audit events and runtime state snapshots in the database schema.
- Created data classes for AuditRecord and RuntimeStateRecord to represent the new entities.
- Implemented AuditRepository and RuntimeStateRepository for inserting and retrieving records.
- Enhanced the dashboard to include an audit trail section, displaying recent audit events.
- Added tests for the new audit repository and runtime lifecycle functionalities.
- Updated settings validation to ensure proper configuration for alerting features.
- Integrated alert notifications across various components, including execution sequencer and loss limits.

tests/unit/test_loss_limits.py

@@ -1,12 +1,39 @@
 from __future__ import annotations
 
+import asyncio
 from datetime import UTC, datetime, timedelta
+from typing import Any
 
 import pytest
 
 from arbitrade.risk.loss_limits import LossLimitGuard
 
 
+class _FakeAlertNotifier:
+    def __init__(self) -> None:
+        self.events: list[dict[str, Any]] = []
+
+    async def notify(
+        self,
+        *,
+        category: str,
+        severity: str,
+        title: str,
+        message: str,
+        details: dict[str, str] | None = None,
+    ) -> bool:
+        self.events.append(
+            {
+                "category": category,
+                "severity": severity,
+                "title": title,
+                "message": message,
+                "details": details or {},
+            }
+        )
+        return True
+
+
 def test_loss_limit_guard_tracks_daily_and_cumulative_pnl() -> None:
     guard = LossLimitGuard(daily_loss_limit=100.0, cumulative_loss_limit=200.0)
     t0 = datetime.now(UTC)
@@ -47,3 +74,17 @@ def test_loss_limit_guard_rejects_invalid_limits() -> None:
 
     with pytest.raises(ValueError, match="cumulative_loss_limit"):
         LossLimitGuard(cumulative_loss_limit=-1.0)
+
+
+@pytest.mark.asyncio
+async def test_loss_limit_guard_emits_alert_on_breach() -> None:
+    notifier = _FakeAlertNotifier()
+    guard = LossLimitGuard(daily_loss_limit=50.0, alert_notifier=notifier)
+
+    guard.register_realized_pnl(-60.0, at=datetime.now(UTC))
+    await asyncio.sleep(0)
+
+    assert guard.is_halted
+    assert len(notifier.events) == 1
+    assert notifier.events[0]["category"] == "threshold"
+    assert notifier.events[0]["title"] == "Daily loss limit breached"