Discover branches/review-pr<N>[-submit] worktrees separately from author
cleanup, fail closed on dirty trees / open PRs / active reviewer leases,
and remove only assessed-safe scratch paths via reconcile.
Implement gitea_reconcile_merged_cleanups with dry-run reporting for merged
PR remote branches and local branches/ worktrees, plus confirmation-gated
execute mode. Safety gates cover protected branches, open PR references,
active issue locks, dirty worktrees, and delete_branch capability.
Closes#269
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>