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/Cli/StellaOps.Cli/Services/Models/TaskRunnerSimulationModels.cs

@@ -0,0 +1,36 @@
+using System.Collections.Generic;
+using System.Text.Json.Nodes;
+
+namespace StellaOps.Cli.Services.Models;
+
+internal sealed record TaskRunnerSimulationRequest(string Manifest, JsonObject? Inputs);
+
+internal sealed record TaskRunnerSimulationResult(
+    string PlanHash,
+    TaskRunnerSimulationFailurePolicy FailurePolicy,
+    IReadOnlyList<TaskRunnerSimulationStep> Steps,
+    IReadOnlyList<TaskRunnerSimulationOutput> Outputs,
+    bool HasPendingApprovals);
+
+internal sealed record TaskRunnerSimulationFailurePolicy(int MaxAttempts, int BackoffSeconds, bool ContinueOnError);
+
+internal sealed record TaskRunnerSimulationStep(
+    string Id,
+    string TemplateId,
+    string Kind,
+    bool Enabled,
+    string Status,
+    string? StatusReason,
+    string? Uses,
+    string? ApprovalId,
+    string? GateMessage,
+    int? MaxParallel,
+    bool ContinueOnError,
+    IReadOnlyList<TaskRunnerSimulationStep> Children);
+
+internal sealed record TaskRunnerSimulationOutput(
+    string Name,
+    string Type,
+    bool RequiresRuntimeValue,
+    string? PathExpression,
+    string? ValueExpression);

src/Cli/StellaOps.Cli/Services/Models/Transport/TaskRunnerSimulationTransport.cs

@@ -0,0 +1,73 @@
+using System.Collections.Generic;
+using System.Text.Json.Nodes;
+
+namespace StellaOps.Cli.Services.Models.Transport;
+
+internal sealed class TaskRunnerSimulationRequestDocument
+{
+    public string Manifest { get; set; } = string.Empty;
+
+    public JsonObject? Inputs { get; set; }
+}
+
+internal sealed class TaskRunnerSimulationResponseDocument
+{
+    public string PlanHash { get; set; } = string.Empty;
+
+    public TaskRunnerSimulationFailurePolicyDocument? FailurePolicy { get; set; }
+
+    public List<TaskRunnerSimulationStepDocument>? Steps { get; set; }
+
+    public List<TaskRunnerSimulationOutputDocument>? Outputs { get; set; }
+
+    public bool HasPendingApprovals { get; set; }
+}
+
+internal sealed class TaskRunnerSimulationFailurePolicyDocument
+{
+    public int MaxAttempts { get; set; }
+
+    public int BackoffSeconds { get; set; }
+
+    public bool ContinueOnError { get; set; }
+}
+
+internal sealed class TaskRunnerSimulationStepDocument
+{
+    public string Id { get; set; } = string.Empty;
+
+    public string TemplateId { get; set; } = string.Empty;
+
+    public string Kind { get; set; } = string.Empty;
+
+    public bool Enabled { get; set; }
+
+    public string Status { get; set; } = string.Empty;
+
+    public string? StatusReason { get; set; }
+
+    public string? Uses { get; set; }
+
+    public string? ApprovalId { get; set; }
+
+    public string? GateMessage { get; set; }
+
+    public int? MaxParallel { get; set; }
+
+    public bool ContinueOnError { get; set; }
+
+    public List<TaskRunnerSimulationStepDocument>? Children { get; set; }
+}
+
+internal sealed class TaskRunnerSimulationOutputDocument
+{
+    public string Name { get; set; } = string.Empty;
+
+    public string Type { get; set; } = string.Empty;
+
+    public bool RequiresRuntimeValue { get; set; }
+
+    public string? PathExpression { get; set; }
+
+    public string? ValueExpression { get; set; }
+}