[dwilding]

What

Follow-up to #208. The bad-token tests assert that nothing is created on disk when the CLI rejects a token. #208 gave them a dedicated, function-scoped dir. This PR drops that fixture and instead has each test remove jubilant from the module-wide test_dir before running, restoring the strict assertion.

Why

• One idiom: the module keeps its single test_dir fixture, matching test_git_errors.py, which also shares one dir across tests.
• Order independence: the reset happens at test start, so test definition order no longer matters (unlike a sequencing approach).
• Less machinery: no second fixture to explain.

Removing jubilant is safe for the rest of the module: the remaining tests each clone their own branch fresh and don't read each other's clones.

Validation

• Full module with a live token: 6/6 pass (the reset path is genuinely exercised, as test_forked_repo_token runs first and creates jubilant).
• Reversed order (test_bad_token_no_owner before test_forked_repo_token): passes.
• ruff check + format: clean.