# Scheduler Exception Lifecycle Worker

## Module
Scheduler

## Status
IMPLEMENTED

## Description
Background worker that monitors exception expiries and triggers policy re-evaluation when exceptions lapse, enforcing time-bounded risk acceptance.

## Implementation Details
- **Exception Lifecycle Worker**: `src/Scheduler/StellaOps.Scheduler.WebService/ExceptionLifecycle/ExceptionLifecycleWorker.cs` -- background `IHostedService` that periodically scans for expiring or expired policy exceptions and triggers re-evaluation of affected findings.
- **Exception Lifecycle Endpoints**: `src/Scheduler/StellaOps.Scheduler.WebService/ExceptionLifecycle/ExceptionLifecycleEndpointExtensions.cs` -- REST endpoints for querying exception status and managing exception lifecycle.
- **Exception Lifecycle Contracts**: `src/Scheduler/StellaOps.Scheduler.WebService/ExceptionLifecycle/ExceptionLifecycleContracts.cs` -- DTOs for exception status, expiry notifications, and lifecycle transitions.
- **Exception Repository**: `src/Scheduler/StellaOps.Scheduler.WebService/ExceptionLifecycle/IExceptionRepository.cs` -- persistence contract for policy exceptions with expiry tracking.
- **Failure Signature Endpoints**: `src/Scheduler/StellaOps.Scheduler.WebService/FailureSignatures/FailureSignatureEndpoints.cs` -- endpoints for managing failure signatures that may trigger exception expiry.
- **Webhook Endpoints**: `src/Scheduler/StellaOps.Scheduler.WebService/EventWebhooks/EventWebhookEndpointExtensions.cs` -- webhook endpoints for notifying external systems of exception lifecycle events.
- **Tests**: `src/Scheduler/__Tests/StellaOps.Scheduler.WebService.Tests/ExceptionLifecycle/ExceptionLifecycleWorkerTests.cs`, `ExceptionLifecycleEndpointsTests.cs`

## E2E Test Plan
- [ ] Create a policy exception with a 1-minute expiry; after expiry, verify the exception lifecycle worker triggers a re-evaluation event for the affected finding
- [ ] Query the exception lifecycle endpoint and verify active exceptions are listed with their remaining TTL
- [ ] Verify exception renewal: extend an exception's expiry before it lapses and confirm the worker does not trigger re-evaluation
- [ ] Verify webhook notification: configure a webhook endpoint and confirm it receives a notification when an exception expires
- [ ] Create multiple exceptions with staggered expiries and verify the worker processes them in expiry order