fix(desktop): preserve WSL runtime installation errors - #21658

💭 Inspecting context for relevance I'm thinking about needing to look over the relevant lines and the context of the tests. It feels crucial to ensure I'm addressing everything accurately. I wonder what specific details I should focus on to make sure I cover all necessary aspects. Let's take it step by step to ensure I understand everything before providing a response. I want to make sure I get this right for the user!

1. browse_code — apps/desktop/src/backend/DesktopBackendConfiguration.ts

2. browse_code — apps/desktop/src/wsl/DesktopWslEnvironment.ts

3. browse_code — apps/desktop/src/{backend,wsl}/*.test.ts

4. browse_code — In apps/desktop/src/backend/DesktopBackendConfiguration.test.ts and apps/desktop/src/wsl/DesktopWslEnvironment.test.ts identify focused regression tests for failed WSL runtime installation preserving diagnostic and shell installer stderr, and whether they mock core business logic or use service test layers. Brief answer with locations.

5. browse_code — Are the DesktopBackendConfiguration WSL tests using mocked core business logic, or just test layers for external services? Specifically describe the harness stubs at lines 212-236 and how they relate to conventions.

6. browse_code — Is the stagedFailure optional runtimeId modification introducing any Effect service conventions violation beyond backend behavior test requirement? Focus on changed lines only.

7. browse_code — Any convention violations in changed shell script lines 277,288 of DesktopWslEnvironment.ts? concise.

8. browse_code — Does anything else affect the no-findings decision?

9. browse_code — Confirm no issue requiring inline review comment for Effect service conventions on this PR.

10. browse_code — Give final verdict in one line.