Finish helper worktrees were living under .omx/agent-worktrees and .omc/agent-worktrees, so VS Code surfaced __source-probe and __integrate repos beside real agent lanes. This moves those helpers into runtime-scoped .tmp-worktrees roots, deletes stale temporary refs at source and in prune sweeps, and extends scan-ignore/test coverage to keep the helper surface internal.

Constraint: Parent workspace view intentionally exposes .omx/agent-worktrees and .omc/agent-worktrees as real SCM lanes
Rejected: Keep helper worktrees under agent roots and only tweak labels | stale repos still surface in SCM and root scans
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Temporary finish helpers are internal-only; do not move them back under agent-worktrees without updating repo-scan ignores and prune behavior
Tested: bash -n scripts/agent-branch-finish.sh scripts/agent-worktree-prune.sh templates/scripts/agent-branch-finish.sh templates/scripts/agent-worktree-prune.sh; node --test test/finish.test.js test/worktree.test.js test/setup.test.js test/metadata.test.js; openspec validate agent-codex-fix-temp-helper-worktree-cleanup-2026-04-23-11-56 --type change --strict
Not-tested: live GitHub PR finish flow on this manually created /tmp worktree lane