feat: Enhance Task Runner with simulation and failure policy support

- Added tests for output projection and failure policy population in TaskPackPlanner.
- Introduced new failure policy manifest in TestManifests.
- Implemented simulation endpoints in the web service for task execution.
- Created TaskRunnerServiceOptions for configuration management.
- Updated appsettings.json to include TaskRunner configuration.
- Enhanced PackRunWorkerService to handle execution graphs and state management.
- Added support for parallel execution and conditional steps in the worker service.
- Updated documentation to reflect new features and changes in execution flow.

src/Scheduler/StellaOps.Scheduler.WebService/GraphJobs/GraphJobUpdateResult.cs

@@ -0,0 +1,8 @@
+namespace StellaOps.Scheduler.WebService.GraphJobs;
+
+internal readonly record struct GraphJobUpdateResult<TJob>(bool Updated, TJob Job) where TJob : class
+{
+    public static GraphJobUpdateResult<TJob> UpdatedResult(TJob job) => new(true, job);
+
+    public static GraphJobUpdateResult<TJob> NotUpdated(TJob job) => new(false, job);
+}