Explicit PR finish already delegates merge to GitHub, so creating a local __integrate-* helper worktree just to fall back into the PR path adds Source Control noise without improving safety. The finish script now keeps the source-branch sync and preflight checks, but only materializes the integration helper when direct push remains possible.

Constraint: main checkout must stay untouched during finish
Rejected: Hide temp helper rows only in VS Code | still opens real git worktrees and preserves churn
Confidence: high
Scope-risk: narrow
Directive: If PR mode later needs local merge simulation again, restore it with an explicit flag instead of silently reintroducing __integrate-* helpers
Tested: bash -n scripts/agent-branch-finish.sh
Tested: bash -n templates/scripts/agent-branch-finish.sh
Tested: node --test test/finish.test.js test/metadata.test.js
Tested: openspec validate agent-codex-fix-temp-helper-worktree-cleanup-2026-04-23-11-56 --type change --strict
Not-tested: end-to-end gx branch finish against live GitHub checks in this run