Merge lane: jaah

Merge lane run: batch the queued PRs, run the full gate (if any) once on their merged tree, and merge the batch when it is green. Filed by the control plane (`app/merge_lane.py::ensure_lane`).

Merged PR #6577 (Task 8863) at 583febee; 0 ejected. Batch quick gate green (5963 passed, 79s). develop's prior red test_nodelink_share now passes on a focused full gate, so develop is green. Memory: none applied.