find_fix.py decides in_head with one rev-list, runs -S as parallel slices and builds the candidate lines in parallel. Verified before the merge on the precomputed merge tree: test_ci_tools 7/7, byte-identical output on 3 calls in the skills repo and 2 in infinito-nexus-core, -S on core 62.4 s to 9.6 s.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>