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_execution_sequencer.py

@@ -10,6 +10,31 @@ from arbitrade.detection.engine import OpportunityEvent
 from arbitrade.execution.sequencer import TriangularExecutionSequencer
 
 
+@dataclass(slots=True)
+class _FakeAlertNotifier:
+    events: list[dict[str, str]] = field(default_factory=list)
+
+    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 or {}),
+            }
+        )
+        return True
+
+
 @dataclass(slots=True)
 class _FakeRestClient:
     fail_at_call: int | None = None
@@ -42,9 +67,11 @@ def _sample_event(cycle: str = "USD->BTC->ETH->USD") -> OpportunityEvent:
 @pytest.mark.asyncio
 async def test_triangular_sequencer_executes_legs_in_order() -> None:
     client = _FakeRestClient()
+    notifier = _FakeAlertNotifier()
     sequencer = TriangularExecutionSequencer(
         client,
         available_pairs=["BTC/USD", "ETH/BTC", "ETH/USD"],
+        alert_notifier=notifier,
     )
 
     result = await sequencer.execute(_sample_event())
@@ -53,14 +80,19 @@ async def test_triangular_sequencer_executes_legs_in_order() -> None:
     assert result.completed_legs == 3
     assert [call["pair"] for call in client.calls] == ["BTC/USD", "ETH/BTC", "ETH/USD"]
     assert [call["side"] for call in client.calls] == ["buy", "buy", "sell"]
+    assert len(notifier.events) == 1
+    assert notifier.events[0]["category"] == "trade"
+    assert notifier.events[0]["title"] == "Trade execution completed"
 
 
 @pytest.mark.asyncio
 async def test_triangular_sequencer_stops_on_failed_leg() -> None:
     client = _FakeRestClient(fail_at_call=2)
+    notifier = _FakeAlertNotifier()
     sequencer = TriangularExecutionSequencer(
         client,
         available_pairs=["BTC/USD", "ETH/BTC", "ETH/USD"],
+        alert_notifier=notifier,
     )
 
     result = await sequencer.execute(_sample_event())
@@ -69,6 +101,9 @@ async def test_triangular_sequencer_stops_on_failed_leg() -> None:
     assert result.completed_legs == 1
     assert result.failure_reason is not None
     assert len(client.calls) == 1
+    assert len(notifier.events) == 1
+    assert notifier.events[0]["category"] == "error"
+    assert notifier.events[0]["title"] == "Trade execution failed"
 
 
 def test_triangular_sequencer_rejects_non_closed_cycle() -> None: