The openRepoTools entry point prints a traceback, not its refusal, when the only bash on PATH cannot be run #256

Found by the independent review of #228's pull request 1 (NIT-2). The code arrives with that pull request.

• Where: src/openrepotools/cli.py:81, at Releases: annotated tags, release/vX.Y branches, and openrepotools on TestPyPI and PyPI from v1.1.0 #228's PR 1 head c1c1c71. main() catches only FileNotFoundError and NotADirectoryError around os.execvp("bash", …).
• The failure:
  • There is no runnable bash, but PATH holds a mode-644 file named bash, or a directory that cannot be searched.
  • os.execvp keeps that EACCES and raises PermissionError.
  • The person gets a traceback and exit 1. They should get the refusal contracts/cli-output.md gives for a missing bash, with exit 2.
• A runnable bash later on PATH is unaffected, because execvp goes on to it.
• How it was shown: a run. env -i PATH=<dir with a mode-644 bash> python3 -c 'from openrepotools.cli import main; …' gave PermissionError: [Errno 13] and exit 1.
• Why it waits: the contract names only "no bash" and "PATH ending in a file", so this edge case is outside it.
• The fix: give PermissionError the same refusal, naming the unrunnable bash. Add a test beside test_entry_'s no-bash cases.

Filed in milestone v1.2.0 on Brett Heap's word (2026-10-18T20:2xZ, "yes, file both as you recommend"). It is unclaimed.

Lane: openRepoTools-3