Audit of london-a rc.conf found several services running but not
captured in host_vars or docs: cloudflared, InfluxDB, Redis,
PostgreSQL, and libvirtd.
- InfluxDB: only _internal db, completely unused
- Redis: empty keyspace, unused
- PostgreSQL: has pez_vps db from a dead project, needs data review
- libvirtd: zero VMs, related to same dead project
- cloudflared: running tunnel 168eccae, config now captured
Also documented the weekly ZFS scrub cron (Sundays at noon) which
is in root's crontab but not ansible-managed.
Ref: PESO-101
- New zfs role with cron-based scrub scheduling for Linux and FreeBSD
- Weekly Sunday scrubs at noon (matching existing manual crons)
- Add zfs_hosts inventory group with london-a and london-b
- Configure zfs_pools per host: zroot (london-a), hdd (london-b)
- Add Prometheus alert rules for degraded/faulted/offline pools
- Add zfs.yml playbook for targeted deploys
Captures the previously untracked scrub cron on london-a and
re-enables the commented-out scrub on london-b.
Refs: PESO-93
