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_settings_validation.py

@@ -0,0 +1,51 @@
+import pytest
+from pydantic import ValidationError
+
+from arbitrade.config.settings import Settings
+
+
+def test_dashboard_auth_requires_both_fields() -> None:
+    with pytest.raises(ValidationError):
+        Settings(_env_file=None, DASHBOARD_AUTH_USERNAME="admin")
+
+
+def test_kraken_api_auth_requires_key_and_secret() -> None:
+    with pytest.raises(ValidationError):
+        Settings(_env_file=None, KRAKEN_API_KEY="key-only")
+
+
+def test_kraken_permissions_require_query_and_trade() -> None:
+    with pytest.raises(ValidationError):
+        Settings(
+            _env_file=None,
+            KRAKEN_API_KEY="k",
+            KRAKEN_API_SECRET="s",
+            KRAKEN_API_KEY_PERMISSIONS="query",
+        )
+
+
+def test_kraken_permissions_forbid_withdrawal_scope() -> None:
+    with pytest.raises(ValidationError):
+        Settings(
+            _env_file=None,
+            KRAKEN_API_KEY="k",
+            KRAKEN_API_SECRET="s",
+            KRAKEN_API_KEY_PERMISSIONS="query,trade,withdraw",
+        )
+
+
+def test_alert_min_severity_is_validated() -> None:
+    with pytest.raises(ValidationError):
+        Settings(_env_file=None, ALERT_MIN_SEVERITY="nope")
+
+
+def test_valid_security_configuration_passes() -> None:
+    settings = Settings(
+        _env_file=None,
+        KRAKEN_API_KEY="k",
+        KRAKEN_API_SECRET="s",
+        KRAKEN_API_KEY_PERMISSIONS="query,trade",
+        ALERT_MIN_SEVERITY="warning",
+    )
+
+    assert settings.kraken_api_key_permissions == "query,trade"