[WIP] Continue processing all subsequent chunks together

[Copilot]

• Phase 3 completion: Add HTTP-level REST API integration tests for JobManager using WebApplicationFactory
• Add public partial class Program {} to JobManager Program.cs for test access
• Add Microsoft.AspNetCore.Mvc.Testing package to test project
• Create RestApiIntegrationTests.cs with 23 HTTP-level integration tests (submit, status, list, cancel, TM registration/heartbeat/unregister, cluster overview, full e2e scenario)
• Fix: Use polling helper (PollForJobStateAsync) instead of brittle fixed delays for state verification
• Fix: Use isolated factory instances for tests requiring clean state
• Update TODO files to mark Phase 3 as 100% complete and document Phase 4 next steps
• Phase 4 preparation: Add Temporal workflow unit tests

---

📍 Connect Copilot coding agent with Jira, Azure Boards or Linear to delegate work to Copilot in one click without leaving your project management tool.

[devstress]

@copilot continue