feat: Implement Scheduler Worker Options and Planner Loop

- Added `SchedulerWorkerOptions` class to encapsulate configuration for the scheduler worker.
- Introduced `PlannerBackgroundService` to manage the planner loop, fetching and processing planning runs.
- Created `PlannerExecutionService` to handle the execution logic for planning runs, including impact targeting and run persistence.
- Developed `PlannerExecutionResult` and `PlannerExecutionStatus` to standardize execution outcomes.
- Implemented validation logic within `SchedulerWorkerOptions` to ensure proper configuration.
- Added documentation for the planner loop and impact targeting features.
- Established health check endpoints and authentication mechanisms for the Signals service.
- Created unit tests for the Signals API to ensure proper functionality and response handling.
- Configured options for authority integration and fallback authentication methods.

docs/deploy/containers.md

@@ -68,7 +68,7 @@ Ensure `AOC_VERIFIER_USER` exists in Authority with `aoc:verify` scope and no wr
 clients:
   - clientId: stella-aoc-verify
     grantTypes: [client_credentials]
-    scopes: [aoc:verify, advisory:verify, vex:verify]
+    scopes: [aoc:verify, advisory:read, vex:read]
     tenants: [default]
 ```