feat: add server, workstation, and cloud edition manifests

Define the three flagship editions as plain-text manifests:

- server (bastion): production server - observability stack, containers.
- workstation (forge): curated KDE Plasma + dev toolchains.
- cloud (nimbus): cloud kernel, cloud-init, guest agents.

Each manifest carries metadata (services to enable/mask), a package
list, a hardened kernel cmdline, and a btrfs fstab template.

editions/cloud/fstab

@@ -0,0 +1,9 @@
+# Arcline Cloud — /etc/fstab template
+# Same layout as the other editions; btrfs-init.sh resolves the root UUID.
+
+UUID=__ROOT_UUID__ /             btrfs   rw,noatime,compress=zstd:3,subvol=@       0 0
+UUID=__ROOT_UUID__ /home         btrfs   rw,noatime,compress=zstd:3,subvol=@home   0 0
+UUID=__ROOT_UUID__ /var/log      btrfs   rw,noatime,compress=zstd:3,subvol=@log    0 0
+UUID=__ROOT_UUID__ /.snapshots   btrfs   rw,noatime,compress=zstd:3,subvol=@snapshots 0 0
+
+/swap/swapfile                  none    swap    sw                          0      0

editions/cloud/kernel.cmdline

@@ -0,0 +1,28 @@
+# Arcline Cloud — kernel command line
+# Same hardening baseline, serial console for cloud serial ports, no graphics.
+
+console=tty0
+console=ttyS0,115200n8
+quiet
+loglevel=3
+systemd.show_status=auto
+
+# hardening
+init_on_alloc=1
+init_on_free=1
+slab_nomerge
+page_poison=1
+pti=on
+spectre_v2=on
+spec_store_bypass=on
+tsx=off
+lockdown=integrity
+oops=panic
+panic=-1
+
+# cloud / disk
+net.ifnames=0
+biosdevname=0
+
+# btrfs / storage
+rootflags=subvol=@

editions/cloud/metadata.yaml

@@ -0,0 +1,36 @@
+# Edition manifest: Arcline Cloud
+# Codename: nimbus
+edition: cloud
+codename: nimbus
+summary: Minimal base images optimized for cloud infrastructures.
+description: >
+  Designed for AWS, GCP, Azure, or your own private cloud. Uses the cloud
+  kernel, cloud-init for first-boot provisioning, and a networkd-first
+  network stack. Same hardening baseline as server.
+
+image:
+  type: iso
+  boot: bios+efi
+  filesystem: btrfs
+  compression: zstd:3
+
+packages:
+  extra_repos: []
+
+users:
+  - arcline
+
+services:
+  enabled:
+    - systemd-networkd
+    - systemd-resolved
+    - cloud-init
+    - cloud-init-local
+    - ssh
+    - nftables
+    - apparmor
+    - qemu-guest-agent
+    - arcline-snapshot.timer
+  masked:
+    - apt-daily.timer
+    - apt-daily-upgrade.timer

editions/cloud/packages.list

@@ -0,0 +1,60 @@
+# Arcline Cloud — package set
+# Minimal footprint: cloud kernel, cloud-init, guest agents, storage tooling.
+
+# ── base system ─────────────────────────────────────────────────────────────
+systemd
+systemd-sysv
+dbus
+libpam-systemd
+ca-certificates
+locales
+tzdata
+
+# ── boot ────────────────────────────────────────────────────────────────────
+grub-pc
+grub-efi-amd64
+shim-signed
+
+# ── kernel (cloud variant) ──────────────────────────────────────────────────
+linux-image-cloud-amd64
+
+# ── filesystem ──────────────────────────────────────────────────────────────
+btrfs-progs
+zstd
+xz-utils
+
+# ── cloud provisioning ──────────────────────────────────────────────────────
+cloud-init
+cloud-guest-utils
+cloud-image-utils
+open-vm-tools
+qemu-guest-agent
+
+# ── storage / block devices ─────────────────────────────────────────────────
+nvme-cli
+open-iscsi
+multipath-tools
+lvm2
+mdadm
+
+# ── security / hardening ────────────────────────────────────────────────────
+openssh-server
+nftables
+apparmor
+apparmor-utils
+
+# ── observability (Debian-main components) ─────────────────────────────────
+prometheus-node-exporter
+
+# ── minimal admin tooling ───────────────────────────────────────────────────
+curl
+jq
+git
+rsync
+htop
+vim-tiny
+
+# ── Arcline toolchain (built from toolchain/) ───────────────────────────────
+# arcline-uptime arcline-check arcline-audit arcline-dns
+# arcline-vault arcline-email arcline-migrate arcline-billing
+# arcline-portal arcline-website arcline-status