Three of the four new tests spawn independent Bun subprocesses but none are marked `test.concurrent`, violating `test/CLAUDE.md`'s guideline to use `test.concurrent` or `describe.concurrent` when multiple tests in the same file spawn processes. Since the three process-spawning tests are fully independent (no shared state), making them concurrent would be straightforward and would reduce CI time.

All three subprocess-spawning tests check `expect(exitCode).toBe(0)` before asserting stdout content, violating the CLAUDE.md mandate that stdout should be checked first. This means if a test fails due to wrong output, the error will report an exit code mismatch rather than showing the actual vs expected stdout, making debugging harder.