Feature/atlas icloudpd migration (#14)

* Design gated Atlas iCloudPD migration target

* Target Atlas iCloudPD photos to Photobook

* Record isolated iCloudPD Photobook ACL validation

* Record Aegis iCloudPD source audit gap

* Verify iCloudPD backup source scope and Borg access

* Record Atlas iCloudPD deployment gate checks

* Pin iCloudPD photo file and directory modes

* Validate inactive iCloudPD Quadlet on Atlas generator

* Keep iCloudPD in Archive and reserve Photobook for Immich

* Prepare guarded Aegis iCloudPD retirement

* Declare inactive Atlas iCloudPD storage and Quadlet

* Retire Aegis iCloudPD from desired state

* Clear retired Aegis iCloudPD failed-unit state

* Remove completed iCloudPD retirement tasks from Aegis

* Record initial Atlas iCloudPD service start

* Manage Atlas iCloudPD config from Vault

* Fix Atlas iCloudPD traceroute startup and config drift

* Use Atlas Vault key for iCloudPD Apple ID

* Add HEIC decoding to Fedora desktops

* Record completed iCloudPD ingestion and remaining recovery checks

ansible/roles/profile_atlas/templates/atlas-icloudpd.container.j2

@@ -0,0 +1,22 @@
+# Managed by Ansible. No install target or automatic start.
+[Unit]
+Description=Atlas rootless iCloud Photos Downloader
+RequiresMountsFor={{ atlas_icloudpd_state_dir }} {{ atlas_icloudpd_photos_dir }}
+
+[Container]
+ContainerName=atlas-icloudpd
+Image={{ atlas_icloudpd_image }}
+UserNS=keep-id:uid=1000,gid=1000
+# The image initialises its unprivileged UID 1000 account as container root.
+User=0
+# Upstream launcher requires traceroute for its iCloud reachability check.
+AddCapability=NET_RAW
+Environment=TZ={{ atlas_icloudpd_timezone }}
+Volume={{ atlas_icloudpd_photos_dir }}:/home/user/iCloud:z
+Volume={{ atlas_icloudpd_config_dir }}:/config:Z
+NoNewPrivileges=true
+
+[Service]
+Restart=on-failure
+RestartSec=300
+TimeoutStartSec=900