Operator approved: 'Kill the stuck apt-get update on the three units'.

Machines all MAAS-Deployed but juju agents pending on machine 5 and containers
0/lxd/10 + 2/lxd/2 (mysql/0 and /2), stalling the cluster and the whole
pre-vault-init settle. Cause: cloud-init modules --mode=final ran apt-get update
at 04:48 and blocked on archive.ubuntu.com (16s CPU over 13h = stuck on I/O);
jujud installs after apt, so the agent never installed. The 12 that came up drew
a healthy path; these 3 hit the flaky-archive-backend class (08-02 F2) and a
blocked process never retries. Both apt proxies tested 200 at fix time -- network
recovered, only the wedged processes held.

Fix: pkill the stuck apt-get update on all three (direct-SSH juju key for the
machine, lxc exec via the host for the containers), clear stale locks. cloud-init
resumed, jujud installed, all three agents came up started; mysql/0+/2 to
maintenance (install), cluster can form.

Logged not fixed: dual apt proxies on the nodes (MAAS + DC); OS cloud-init apt
not pinned to the resilient DC proxy. DC-standup hardening candidates.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HvCyrwvYTTcDYnRErfMsNf