skydick: add mirrored NVMe special vdev + mirrored SLOG ...

Replaced single-drive SLOG + L2ARC with dual-Optane mirrored setup:
- 690G mirrored special vdev for metadata + files ≤128K
- 8G mirrored SLOG for sync writes
- special_small_blocks=128K set in ZFS properties service
- nvme1 formatted to 4Kn to match nvme0

The special vdev is the biggest performance win for an HDD pool: all
metadata lookups, directory listings, and small files now hit NVMe.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

skydick: document drive10 added as second hot spare ...

sg_format completed on drive10 (c9bcfa0f). Both LUNs added as spares,
bringing the pool to 8 mirrors + 2 hot spares (4 spare LUNs total).

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

skydick: document pool expansion to 8 mirrors (~50.9T) ...

Added 4 new SAS Mach2 drives (drive6-9) as 4 mirror vdevs. Updated
drive inventory, layout diagram, expansion commands, and runbook
with sg_format/wipefs steps. drive10 pending sg_format completion.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

skydick: document Windows NFS client path differences ...

Co-Authored-By: Claude Opus 4.6 <[email protected]>

skydick: clean SMB tuning and enforce datapool atime

skydick: document datapool user and admin workflow

skydick: keep SMB passwords synced from LDAP

skydick: update DATAPOOL.md for ldapsam, ye-lw21 rename, and storage group model ...

Co-Authored-By: Claude Opus 4.6 <[email protected]>

skydick: enable LDAP-backed NSS for POSIX identity resolution ...

Add users.ldap with nslcd pointed at ldap://10.0.0.1/ for passwd/group
lookups. This is identity-only: loginPam=false keeps SSH/console auth
local, and Samba stays on tdbsam until sambaSamAccount objects exist
in LDAP.

- Add agenix secret for LDAP bind credential (cn=query_user)
- nss_initgroups_ignoreusers ALLLOCAL avoids boot-time NSS deadlock
- Add openldap package for admin ldapsearch/ldapmodify
- Update DATAPOOL.md to reflect LDAP identity model, numeric UID/GID
  in tmpfiles for LDAP-only users, and current auth boundaries

Co-Authored-By: Claude Opus 4.6 <[email protected]>

skydick: redesign datapool with per-user datasets and service model ...

Replace flat purpose-first layout (share/media/torrent/backup/vm) with
user-first hierarchy:

- dick/public: shared collaborative files
- dick/media: shared media with data/ + library/ in one hardlink domain
- dick/users/<user>/{files,bt-state,vm}: per-user private trees with
  ZFS quotas, per-user NFS all_squash, and Samba [homes]
- dick/system/{backup,vm}: admin-only system datasets
- dick/templates/vm: read-only shared VM base images

NFS exports split media into rw writer (all_squash to qbittorrent) and
ro reader (/media/library).  Per-user exports use explicit anonuid/gid.
Samba uses [public] for shared, [homes] for per-user, [media] ro for
library.  Legacy exports preserved for active migration.

Add DATAPOOL.md with user/admin guide covering SMB/NFS connection,
new-user provisioning, quotas, and troubleshooting.

Co-Authored-By: Claude Opus 4.6 <[email protected]>