Implements issue #409: a serial Mergify merge queue that supersedes the
hand-rolled poor-man's queue (autoupdate.yml + ci-trigger.yml +
traffic-control.yml, all already disabled_manually).
- queue_rules "default": batch_size 1 (serial, no batching), merge_method
merge (merge commits, never squash/rebase), merge_conditions gate on
check-success = "CI passed" + -draft + -conflict + label != broken.
- merge_queue.max_parallel_checks 1 (true serial; unambiguously
require-up-to-date-compatible).
- priority_rules map P0..P9 labels (P0 = 10000 highest .. P9 = 1000).
- pull_request_rules queue action triggers auto-queueing (queue_conditions
alone do NOT auto-queue per Mergify lifecycle docs).
require-up-to-date STAYS ON (Phase 1 is the only trilemma combo that keeps
the checkbox literally enabled AND preserves merge commits). No batching
(that is Phase 2 / #410). Single required gate stays "CI passed".
Validated: YAML parses and conforms to Mergify's published JSON schema
(negative-control confirmed). Merging this activates Mergify, so NO
auto-merge — must be reviewed first.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
JMR-devandClaude Opus 4.8