Add a wrong-reason failure classification fixture

[YamaTro]

Background

ReproProof must distinguish an intended assertion failure from a setup or unrelated failure. A missing-pytest false positive was already found and fixed; broader wrong-reason coverage is needed.

Implementation scope

Add one controlled Node or Python fixture whose candidate exits nonzero for an unrelated reason (for example, a safe import/collection error), and prove the adapter returns inconclusive rather than reproduced.

Likely files

• fixtures/issues/
• fixtures/node-test/ or fixtures/python-pytest/
• tests/e2e/
• optionally packages/language-node/src/index.ts or packages/language-python/src/index.ts

Acceptance criteria

• Fixture is minimal, original, and Apache-2.0-compatible.
• The candidate exits nonzero for the documented unrelated reason.
• ReproProof reports inconclusive, with an understandable assessment note.
• Existing verified reproductions remain reproduced.
• corepack pnpm check succeeds.

Test method

Run the new focused E2E test, then corepack pnpm check. Include the relevant sanitized report excerpt in the PR.

Difficulty

Beginner-to-intermediate. The main challenge is expressing the evidence boundary, not writing a large amount of code.

Questions

Comment on this issue with the proposed failure mode before implementing so maintainers can confirm it is safe and non-duplicative.