LeanerCloud

Drive a PR (or list of PRs, or all eligible open PRs in the current repo) to merge-ready state by resolving conflicts, addressing CodeRabbit (CR) findings, re-pinging CR, and iterating until CR has zero actionables and CI is green. Invocations - `/pr-iterate <PR#>` (single), `/pr-iterate <PR#> <PR#> ...` (parallel fan-out across the listed PRs), `/pr-iterate` (fan out across all eligible open PRs in current repo, with a confirmation gate). Triggered by user requests like "address CR on