The conflict-resolution rebase incorrectly kept ISSUE_LOCK_FILE in the
merged_cleanup_reconcile import, but that symbol was moved to
issue_lock_provenance on master. This broke webui import collection.
Fixes the reviewer-reported regression on PR #448.
Adds read-only /leases and /api/leases routes for issue claim inventory,
reviewer PR lease comments, duplicate PR/branch warnings, and local issue
lock visibility without acquire/release mutations.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>