Integrate G15 submodules with Debian 13 packaging and devcontainer

packaging/rebuild.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+# Standalone source QA: mount artifacts and this script, NOT the repository.
+set -euo pipefail
+export LC_ALL=C
+[[ -f /.dockerenv && $EUID == 0 ]] || exit 1
+out=$(realpath "${1:?artifact directory}")
+(cd "$out" && sha256sum -c SHA256SUMS)
+work=$(mktemp -d)
+trap 'rm -rf "$work"' EXIT
+export DEB_BUILD_OPTIONS=parallel=2
+for source in libg15 libg15render g15daemon g15macro; do
+    mkdir "$work/$source"
+    cd "$work/$source"
+    dsc=("$out/${source}_"*.dsc)
+    [[ ${#dsc[@]} == 1 ]]
+    dpkg-source -x "${dsc[0]}" tree
+    cd tree
+    apt-get build-dep -y .
+    dpkg-buildpackage -us -uc -b
+    cd ..
+    apt-get install -y ./*.deb
+done
+echo 'PASS: all four source artifacts rebuilt standalone in dependency order.'