feat: scaffold Arcline OS build system

Scaffold the Arcline OS build system ("the wires"): a transparent,
auditable pipeline that turns a Debian bookworm base into hardened OS
images for the server, workstation, and cloud editions.

- Makefile orchestrates everything (make iso-<edition>, check, test,
  toolchain, clean); versions.mk is the single source of truth for
  versions and paths.
- scripts/ is the plain-bash pipeline: debootstrap -> install packages
  -> apply overlays -> in-chroot configure -> live ISO, plus a rootfs
  archive along the way.
- ARCLINE_TOOLCHAIN=auto|skip|require controls whether the 11 Go tools
  are bundled into an image (auto by default; minimal builds available
  via make iso-<edition>-minimal).
- GPL-3.0 licensed, sponsored by Arcline IT LLC.

LICENSE

@@ -0,0 +1,20 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2026 Arcline IT LLC
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+The full text of the license is available at:
+    https://www.gnu.org/licenses/gpl-3.0.txt