…behavior

This finishes the pending CI drift cleanup by teaching branch-finish to honor stored guardexBase metadata and by bringing the focused test expectations back in line with the current branch naming, gitignore, self-update, and codex-agent output contracts. The change is migrated onto current main so it does not drag stale base-state back into the merge.\n\nConstraint: the fix must stay narrow to current CLI/test contract drift rather than reworking unrelated codex-agent hang behavior\nRejected: commit the old stale-base worktree directly | risked reintroducing already-merged base-state churn\nConfidence: medium\nScope-risk: narrow\nDirective: keep branch-name and output expectation updates tied to real runtime behavior; do not rewrite tests toward a hoped-for contract\nTested: named node --test run for changed doctor/start/finish/metadata cases (9 passing); node --test self-update reexec case; node --test codex-agent launch case; node --test codex-agent --codex-bin override case; openspec validate agent-codex-fix-remaining-cli-ci-failures-2026-04-21-11-42 --type change --strict; openspec validate --specs; git diff --check\nNot-tested: node --test --test-name-pattern codex-agent restores local branch and falls back to safe worktree start when starter script switches in-place test/install.test.js timed out after 120s