Implement MongoDB-based storage for Pack Run approval, artifact, log, and state management

- Added MongoPackRunApprovalStore for managing approval states with MongoDB.
- Introduced MongoPackRunArtifactUploader for uploading and storing artifacts.
- Created MongoPackRunLogStore to handle logging of pack run events.
- Developed MongoPackRunStateStore for persisting and retrieving pack run states.
- Implemented unit tests for MongoDB stores to ensure correct functionality.
- Added MongoTaskRunnerTestContext for setting up MongoDB test environment.
- Enhanced PackRunStateFactory to correctly initialize state with gate reasons.

src/TaskRunner/StellaOps.TaskRunner/StellaOps.TaskRunner.Tests/PackRunStateFactoryTests.cs

@@ -0,0 +1,40 @@
+using StellaOps.TaskRunner.Core.Execution;
+using StellaOps.TaskRunner.Core.Execution.Simulation;
+using StellaOps.TaskRunner.Core.Planning;
+using StellaOps.TaskRunner.Core.TaskPacks;
+
+namespace StellaOps.TaskRunner.Tests;
+
+public sealed class PackRunStateFactoryTests
+{
+    [Fact]
+    public void CreateInitialState_AssignsGateReasons()
+    {
+        var manifest = TestManifests.Load(TestManifests.Sample);
+        var planner = new TaskPackPlanner();
+        var planResult = planner.Plan(manifest);
+
+        Assert.True(planResult.Success);
+        Assert.NotNull(planResult.Plan);
+        var plan = planResult.Plan!;
+
+        var context = new PackRunExecutionContext("run-state-factory", plan, DateTimeOffset.UtcNow);
+        var graphBuilder = new PackRunExecutionGraphBuilder();
+        var graph = graphBuilder.Build(plan);
+        var simulationEngine = new PackRunSimulationEngine();
+
+        var timestamp = DateTimeOffset.UtcNow;
+        var state = PackRunStateFactory.CreateInitialState(context, graph, simulationEngine, timestamp);
+
+        Assert.Equal("run-state-factory", state.RunId);
+        Assert.Equal(plan.Hash, state.PlanHash);
+
+        Assert.True(state.Steps.TryGetValue("approval", out var approvalStep));
+        Assert.Equal(PackRunStepExecutionStatus.Pending, approvalStep.Status);
+        Assert.Equal("requires-approval", approvalStep.StatusReason);
+
+        Assert.True(state.Steps.TryGetValue("plan-step", out var planStep));
+        Assert.Equal(PackRunStepExecutionStatus.Pending, planStep.Status);
+        Assert.Null(planStep.StatusReason);
+    }
+}