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/AdvisoryAI/StellaOps.AdvisoryAI/Diagnostics/AdvisoryAiActivitySource.cs

@@ -0,0 +1,8 @@
+using System.Diagnostics;
+
+namespace StellaOps.AdvisoryAI.Diagnostics;
+
+internal static class AdvisoryAiActivitySource
+{
+    public static readonly ActivitySource Instance = new("StellaOps.AdvisoryAI");
+}