chore: base Arcline OS on Debian trixie (current stable)

Bookworm became oldstable in July 2026 (standard support ended
2026-07-11). A new distro should be built on the current stable, which
is now Trixie (13.6): newer kernel (6.12 LTS vs 6.1, whose LTS ends Dec
2026), newer systemd/containers/toolchains, KDE 6 for the workstation
edition, and a year of stability behind it (full support until
2028-08-09).

- versions.mk / common.sh: DEBIAN_SUITE bookworm -> trixie, kernel 6.1 -> 6.12
- package list header comments: bookworm -> trixie
- GitLab CI: debian:bookworm -> debian:trixie build images
- docs (architecture, building): base references updated

All packages used across the three editions exist in Trixie unchanged.

ci/.gitlab-ci.yml

@@ -4,7 +4,7 @@
 # Mirrors the local build flow (scripts/ + Makefile) in CI:
 #   validate → build (matrix over editions) → test → publish
 #
-# The build image is Debian bookworm with the host deps installed, matching
+# The build image is Debian trixie with the host deps installed, matching
 # what scripts/check-host-deps.sh expects locally.
 # ─────────────────────────────────────────────────────────────────────────────
 stages:
@@ -20,7 +20,7 @@ variables:
 # ── validate ────────────────────────────────────────────────────────────────
 validate:
   stage: validate
-  image: debian:bookworm
+  image: debian:trixie
   script:
     - apt-get update -qq && apt-get install -y -qq make bash
     - make check
@@ -28,7 +28,7 @@ validate:
 # ── build (one job per edition) ─────────────────────────────────────────────
 .build:
   stage: build
-  image: debian:bookworm
+  image: debian:trixie
   before_script:
     - apt-get update -qq
     - apt-get install -y -qq debootstrap squashfs-tools grub2-common xorriso cpio curl git make bash gdisk parted rsync dosfstools qemu-utils unzip dpkg openssl sbsigntool
@@ -63,7 +63,7 @@ build-cloud:
 # ── test ────────────────────────────────────────────────────────────────────
 test:
   stage: test
-  image: debian:bookworm
+  image: debian:trixie
   needs: [build-server, build-workstation, build-cloud]
   before_script:
     - apt-get update -qq && apt-get install -y -qq bash make xz-utils

docs/architecture.md

@@ -18,7 +18,7 @@ the product; this repository is how it gets built.
 
 ```mermaid
 flowchart LR
-    A[editions/* metadata] --> B[debootstrap<br/>Debian bookworm]
+    A[editions/* metadata] --> B[debootstrap<br/>Debian trixie]
     B --> C[install edition<br/>packages.list]
     C --> D[apply overlays<br/>base + edition]
     D --> E[configure-system.sh<br/>in chroot]

docs/building.md

@@ -73,7 +73,7 @@ Set these as environment variables or edit `versions.mk`:
 | Variable | Meaning | Default |
 |----------|---------|---------|
 | `VERSION` | release version string | `0.1.0` |
-| `DEBIAN_SUITE` | Debian base | `bookworm` |
+| `DEBIAN_SUITE` | Debian base | `trixie` |
 | `ARCH` | target architecture | `amd64` |
 | `DEBIAN_MIRROR` | mirror for the base | `http://deb.debian.org/debian` |
 | `ARCLINE_LIVE` | install live-boot into rootfs | unset (set by ISO build) |

editions/server/packages.list

@@ -1,5 +1,5 @@
 # Arcline Server — package set
-# Debian bookworm packages. Lines beginning with # are notes/optional.
+# Debian trixie packages. Lines beginning with # are notes/optional.
 # The configure hook installs the Arcline toolchain and observability
 # components that are not in Debian main (grafana, loki).
 

scripts/common.sh

@@ -13,12 +13,12 @@ set -euo pipefail
 : "${DISTRO_ID:=arclineos}"
 : "${VERSION:=0.1.0}"
 : "${RELEASE_NAME:=arclines}"
-: "${DEBIAN_SUITE:=bookworm}"
+: "${DEBIAN_SUITE:=trixie}"
 : "${DEBIAN_MIRROR:=http://deb.debian.org/debian}"
 : "${SECURITY_MIRROR:=http://security.debian.org/debian-security}"
 : "${ARCH:=amd64}"
 : "${KERNEL_PACKAGE:=linux-image-amd64}"
-: "${KERNEL_VERSION:=6.1}"
+: "${KERNEL_VERSION:=6.12}"
 
 # Toolchain policy for image builds:
 #   auto    (default) install the Arcline tools if build/debs/*.deb exist,

versions.mk

@@ -12,8 +12,8 @@ DISTRO_ID     := arclineos
 VERSION       := 0.1.0
 RELEASE_NAME  := arclines
 
-# Debian base we build on. Bookworm = Debian 12 stable.
-DEBIAN_SUITE  := bookworm
+# Debian base we build on. Trixie = Debian 13 stable.
+DEBIAN_SUITE  := trixie
 DEBIAN_MIRROR := http://deb.debian.org/debian
 SECURITY_MIRROR := http://security.debian.org/debian-security
 
@@ -21,9 +21,9 @@ SECURITY_MIRROR := http://security.debian.org/debian-security
 # stretch goal. Kept in one place so adding arm64 is a one-line change.
 ARCH          := amd64
 
-# Kernel flavour shipped by the base. Bookworm ships 6.1 LTS.
+# Kernel flavour shipped by the base. Trixie ships 6.12 LTS.
 KERNEL_PACKAGE := linux-image-amd64
-KERNEL_VERSION := 6.1
+KERNEL_VERSION := 6.12
 
 # Edition codenames (the "what do I install" flavours).
 EDITIONS      := server workstation cloud