Fix worktree cleanup merged classifier

[chubes4]

Summary

• Forward the positional repo/worktree scope for workspace worktree cleanup so repo-scoped dry-runs do not execute as global cleanup.
• Classify clean branches with zero commits outside the repo default ref as merged_to_default before broader patch-equivalence or remote-tracking labels.
• Let active-no-signal-merged-apply accept clean rows with current commits_outside_default === 0, then revalidate through the existing live merged-to-default evidence path.

Verification

• php tests/worktree-cleanup-patch-equivalence.php
• php tests/worktree-cleanup-cli-scope.php
• for f in tests/*.php; do php "$f" || exit $?; done

Notes

• The active local Studio site is still loading wp-content/plugins/data-machine-code, not this branch, so live wp-build cleanup dry-run evidence should be rerun after this branch is installed or merged.

AI assistance

• AI assistance: Yes
• Tool(s): GPT-5.5 via OpenCode
• Used for: Diagnosing and fixing the worktree cleanup merged-branch classifier exposed while cleaning wp-build merged worktrees.