back up Gitea + Skudak app data; drop PartKeepr and Pi-hole

Extends the Nextcloud backup machinery rather than adding a second
mechanism. cloud-backup.sh.j2 gains three guarded options, all no-ops for
the existing callers:

  backup_podman_user  Gitea runs rootless under `git`, not `podman`
  backup_db_type      postgres (Gitea) and mysql (BookStack) alongside
                      mariadb; each engine's completion trailer differs,
                      and grepping for the wrong one fails every run
  backup_sqlite_dbs   `sqlite3 .backup` for live WAL-mode SQLite, gated on
                      `pragma integrity_check` before promotion -- rsync
                      is either stale (no -wal) or torn (with it)

New instances: gitea-debyl, skudak-gitea, bookstack, partsy-skudak. The
alert handler is rendered once and shared, so its wording is now generic
rather than per-product; TAG stays nextcloud-backup because an external
Graylog rule matches on it.

`apply:` on the includes is load-bearing -- tags on a dynamic
include_tasks do not reach the tasks inside it.

Business data (skudak-gitea, bookstack, partsy-skudak) goes to TrueNAS
and on to Skudak's own iDrive account; the personal bucket's
/skudak*/** excludes are permanent, not a stopgap.

Removals: PartKeepr is superseded by Partsy, and its teardown never
finished -- it targeted /etc/systemd/system/podman-partkeepr*.service,
wrong prefix and wrong scope, leaving enabled user units in failed state.
Pi-hole's role was already orphaned (absent from deploy_home.yml); its
port 53 rule went with it after confirming nothing listens there.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ansible/roles/podman/defaults/main.yml

@@ -24,7 +24,6 @@ gregtime_path: "{{ podman_volumes }}/gregtime"
 hass_path: "{{ podman_volumes }}/hass"
 # nginx_path: removed - nginx no longer used
 # nosql_path: removed - nosql/redis no longer used
-partkeepr_path: "{{ podman_volumes }}/partkeepr"
 partsy_path: "{{ podman_volumes }}/partsy"
 partsy_skudak_path: "{{ podman_volumes }}/partsy-skudak"
 photos_path: "{{ podman_volumes }}/photos"
@@ -75,7 +74,6 @@ zomboid_maps:
   modded: "Muldraugh, KY"
   b42revamp: "AnruisiTown;Asakusa lake town;BananaBeachHouse;Blackstone;Cathaya Valley2.0;Cathaya Valley2.0 highway;Daisy County;DawnTown;Estate 39;Fort Waterfront B42;Greenleaf;GreenRiver;IrisEyot;Louisville_Quarantine_Zone;Louisville_River_Marina;Louisville_Riverboat;Maplewood;Meiya'sTown;Muldraugh_FireDept;muldraughmilitarybaseas24;PeaceTown;RaccoonCity;Raven Creek B42;map_distanciado;rvupdate;rv2;serenitybunker;Tikitown;Uncle Red's Bunker B42;Uncle Red's Bunker Redux B42;WestPoint-MilitaryTugBoat;Muldraugh, KY"
 
-pihole_path: "{{ podman_volumes }}/pihole"
 sshpass_cron_path: "{{ podman_volumes }}/sshpass_cron"
 caddy_path: "{{ podman_volumes }}/caddy"