extract docker tooling to ../sbo-dockerbuild

The test-build tool and image-builder chain grew from a .extras/ helper into a
standalone toolchain, now maintained in its own repo (../sbo-dockerbuild). Remove
them here (scripts, examples, design docs) and repoint CLAUDE.md: test-building
is now done with the installed `test-build` CLI, deps resolved from the SBo tree,
both trees verified per bump. Package-maintenance files stay: nvchecker.toml,
hooks/, assets/.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 0 insertions, 69 deletions

diff --git a/.extras/image-builder/README b/.extras/image-builder/README
deleted file mode 100644
index fccab11..0000000
--- a/.extras/image-builder/README
+++ /dev/null
@@ -1,69 +0,0 @@
-sbo-testbuild image builder
-===========================
-
-Builds the docker images that .extras/test-build consumes:
-  docker.noland.dnx:5000/sbo-testbuild:current
-  docker.noland.dnx:5000/sbo-testbuild:15.0
-
-Three scripts, chained (see .extras/docs/specs/2026-07-13-image-builder-design.md):
-  bootstrap.sh           sbo-base:{ver}       FROM scratch, base pkgs from NAS
-  build-full-image.sh    sbo-full:{ver}       FROM base, all series
-  build-sbo-testbuild.sh sbo-testbuild:{ver}  FROM full, + sbopkg + tools
-
-All settings live in ./config.
-
-VM setup (docker.noland.dnx, Slackware x86_64, 4 vCPU / 4 GB / 80 GB)
---------------------------------------------------------------------
-1. Install docker; enable the daemon.
-
-2. NFS-mount the two NAS trees read-only, named to match:
-     /mnt/nas/slackware64-current   -> -current mirror tree
-     /mnt/nas/slackware64-15.0      -> 15.0 mirror tree
-   Each is a full mirror (PACKAGES.TXT, ChangeLog.txt, slackware64/, patches/,
-   extra/). Root must be able to read them (bootstrap runs installpkg as root).
-
-3. Run a LAN registry:
-     docker run -d --restart=always -p 5000:5000 \
-       -v /opt/registry/data:/var/lib/registry --name registry registry:2
-
-4. Mark the registry insecure (plain HTTP) on the VM AND every pulling client
-   (this dev box, the buildsystem VM). In /etc/docker/daemon.json:
-     { "insecure-registries": ["docker.noland.dnx:5000"] }
-   then restart docker.
-
-5. Drop the two prebuilt packages (built once, re-drop on upstream bumps):
-     /opt/sbo-testbuild/pkgs/sbopkg-*.txz
-     /opt/sbo-testbuild/pkgs/sbo-maintainer-tools-*.txz
-
-6. Install the nightly cron (root). The NAS repos sync at 01:00 and 02:00, so
-   the chain runs after and both variants are ready well before the ~09:00 work
-   start. No --force: each script self-gates (bootstrap on the ChangeLog hash,
-   full-image on the base-image digest, build-sbo-testbuild on the full-image
-   digest + tools .txz hash), so an unchanged night is a cheap no-op. -current
-   moves daily and rebuilds most nights; 15.0 is frozen stable and rebuilds only
-   on a real repo update. Deployed schedule on docker.noland.dnx:
-      # -current (ready ~04:35)
-      0  3 * * *  /path/to/.extras/image-builder/bootstrap.sh           --version current >> /var/log/sbo-testbuild.log 2>&1
-     20  3 * * *  /path/to/.extras/image-builder/build-full-image.sh    --version current >> /var/log/sbo-testbuild.log 2>&1
-     30  4 * * *  /path/to/.extras/image-builder/build-sbo-testbuild.sh --version current >> /var/log/sbo-testbuild.log 2>&1
-      # 15.0 (ready ~06:35)
-      0  5 * * *  /path/to/.extras/image-builder/bootstrap.sh           --version 15.0 >> /var/log/sbo-testbuild.log 2>&1
-     20  5 * * *  /path/to/.extras/image-builder/build-full-image.sh    --version 15.0 >> /var/log/sbo-testbuild.log 2>&1
-     30  6 * * *  /path/to/.extras/image-builder/build-sbo-testbuild.sh --version 15.0 >> /var/log/sbo-testbuild.log 2>&1
-
-7. Ensure docker.noland.dnx resolves on the LAN (static IP or DNS).
-
-Manual first run
-----------------
-   ./bootstrap.sh --version current --force
-   ./build-full-image.sh --version current --force
-   ./build-sbo-testbuild.sh --version current --force
-Then confirm:
-   docker pull docker.noland.dnx:5000/sbo-testbuild:current
-   docker run --rm docker.noland.dnx:5000/sbo-testbuild:current sbopkg -V
-
-Flags: --force (rebuild unconditionally), --version <current|15.0> (one variant).
-
-Tests
------
-   bash test-image-builder.sh     # pure-logic self-check, no docker