Write tests no longer pick a random open PR. RUN_WRITE_TESTS=true alone is not
sufficient — TEST_PR_ID must also be set, otherwise each write test is skipped
with a warning. Added try/finally cleanup blocks so approval/comment/task state
is always restored even on assertion failures. Updated .env.example and README
to document the new requirement.
Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
