build-testslisted

# Build Tests Mode Plan and build tests for the current feature branch. ## Additional test focus "$ARGUMENTS" If provided, the above gives optional extra constraints or focus areas for test planning. By default, the skill plans and builds tests for all current branch changes without needing any arguments. ## Process Use a subagent to carry out the following 2 phases sequentially: ### Phase 1: Test Planning - Read the plan file (`plan-*.md`) in the current working directory to understand what was built and why - Read the implementation code — explore all files changed on this branch - Run `git diff origin/main...HEAD` to see all changes - Produce a test plan covering: - What modules/functions/classes need testing - What behaviors and edge cases to cover - What integration points to verify - What NOT to mock (and why) - What testing approach for each component (unit vs integration vs E2E) ### Phase 2: Test Building Write tests following the test plan from Phase 1. Run all tests and fix any failures before finishing. #### Mocking Rules — CRITICAL **Unit tests — mocks are fine:** - Mocks are the standard way to isolate the unit under test. Use them to stub dependencies so you can test one module in isolation. - NEVER mock the code under test itself — that defeats the purpose. - Keep mocks focused: if you need more than 2-3 mocks in a single test, the design may need rethinking. **Integration tests — NO mocks:** - Wire real components together. The whole poin