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/InMemoryGraphJobStore.cs

@@ -1,4 +1,5 @@
-using System.Collections.Concurrent;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
 using StellaOps.Scheduler.Models;
 
 namespace StellaOps.Scheduler.WebService.GraphJobs;
@@ -60,17 +61,37 @@ internal sealed class InMemoryGraphJobStore : IGraphJobStore
         return ValueTask.FromResult<GraphOverlayJob?>(null);
     }
 
-    public ValueTask<GraphBuildJob> UpdateAsync(GraphBuildJob job, CancellationToken cancellationToken)
-    {
-        _buildJobs[job.Id] = job;
-        return ValueTask.FromResult(job);
-    }
-
-    public ValueTask<GraphOverlayJob> UpdateAsync(GraphOverlayJob job, CancellationToken cancellationToken)
-    {
-        _overlayJobs[job.Id] = job;
-        return ValueTask.FromResult(job);
-    }
+    public ValueTask<GraphJobUpdateResult<GraphBuildJob>> UpdateAsync(GraphBuildJob job, GraphJobStatus expectedStatus, CancellationToken cancellationToken)
+    {
+        if (_buildJobs.TryGetValue(job.Id, out var existing) && string.Equals(existing.TenantId, job.TenantId, StringComparison.Ordinal))
+        {
+            if (existing.Status == expectedStatus)
+            {
+                _buildJobs[job.Id] = job;
+                return ValueTask.FromResult(GraphJobUpdateResult<GraphBuildJob>.UpdatedResult(job));
+            }
+
+            return ValueTask.FromResult(GraphJobUpdateResult<GraphBuildJob>.NotUpdated(existing));
+        }
+
+        throw new KeyNotFoundException($"Graph build job '{job.Id}' not found.");
+    }
+
+    public ValueTask<GraphJobUpdateResult<GraphOverlayJob>> UpdateAsync(GraphOverlayJob job, GraphJobStatus expectedStatus, CancellationToken cancellationToken)
+    {
+        if (_overlayJobs.TryGetValue(job.Id, out var existing) && string.Equals(existing.TenantId, job.TenantId, StringComparison.Ordinal))
+        {
+            if (existing.Status == expectedStatus)
+            {
+                _overlayJobs[job.Id] = job;
+                return ValueTask.FromResult(GraphJobUpdateResult<GraphOverlayJob>.UpdatedResult(job));
+            }
+
+            return ValueTask.FromResult(GraphJobUpdateResult<GraphOverlayJob>.NotUpdated(existing));
+        }
+
+        throw new KeyNotFoundException($"Graph overlay job '{job.Id}' not found.");
+    }
 
     public ValueTask<IReadOnlyCollection<GraphOverlayJob>> GetOverlayJobsAsync(string tenantId, CancellationToken cancellationToken)
     {