[CBEPX]

Cancellation on macOS could fail after a launcher execed Claude because the saved identity included its executable name. Use a versioned kernel birth-time identity across exec, preserve ambiguous legacy records, and refuse signals when identity cannot be verified.

Parent message boundaries now keep progress text out of the final answer while preserving terminal-tail recovery within the final message. Qualify Opus 5.5 and Fable 5.1 handling: retain structured terminal failures, expose requested effort, emit content-free thinking progress, and update task guidance. Effort defaults remain unchanged.

Validation: 1160 tests pass under coverage; lines 92.86%, branches 84.29%, functions 97.82%. Lint, both typechecks, version/changelog checks, and 12 lifecycle tests pass. Real Claude task/resume/review/peer checks pass. Packed-plugin cancellation before/after exec, real parser replay, and native Codex manifest checks pass; all 93 packaged files match source. Independent review found no blocking issues.

Twelve controlled model runs match provider terminal output; seven return bare JSON and five include provider-generated code fences. This does not establish comparative model quality or justify new defaults.

1.7.6 is published through #58. Local 1.7.7 installation and qualification passed: all 93 cache files match the archive; setup is ready with four trusted hooks; real task/resume/review/peer, both approved Brave tools, before/after-exec cancellation, parser output, and a fresh Codex client using the installed rescue skill pass. All hosted checks, including mutation, are green. Finish active jobs and resolve cancel_failed jobs before upgrade or rollback.

Known minor follow-up inherited from 1.7.6: a fractional reaper timeout can defer stale-job cleanup. The test-only fix for #57 is inherited from the 1.7.6 branch.