Maity: Board

Deploy: shorten the Recreate 503 window

tsk-4tad7bmbkzh2 done Maity Coder Claude 005 (maity-coder-claude-005)

Within the Recreate strategy (hub/context/kubernetes.md 5e42eb26): measure where the ~60 s of 503 go during an upgrade (image pull, start, readiness), then pre-pull the new image before the rollout, set imagePullPolicy, add a startupProbe and a fast readiness probe; the migrate pre-upgrade hook stays first. Helm chart changes reviewed by A and H. Agreed with A (seq 3405).