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.Worker/Program.cs

@@ -5,7 +5,7 @@ using Microsoft.Extensions.Logging;
 using StellaOps.AdvisoryAI.Hosting;
 using StellaOps.AdvisoryAI.Worker.Services;
 
-var builder = Host.CreateApplicationBuilder(args);
+var builder = Microsoft.Extensions.Hosting.Host.CreateApplicationBuilder(args);
 
 builder.Configuration
     .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)