lmcp: Debian packaging + CI publish via hertz reprepro

- debian/lmcp/build-deb.sh fetches the v0.3.0 tarball, lays out the
  filetree, and uses dpkg-deb to assemble lmcp_0.3.0-1_all.deb directly
  on the Arch aarch64 runner (no debhelper needed for a pure-Lua pkg).
- workflow job 'lmcp-debian' rsyncs the .deb to hertz's marfritrepo
  incoming dir, then ssh-triggers 'publish-deb <suite>' for both
  bookworm and trixie. publish-deb wraps 'reprepro includedeb' and
  rsyncs dists/+pool/ to nc.
- New secret MARFRIT_REPO_HERTZ_KEY uploaded to Gitea repo. Forced
  command on hertz routes rsync uploads vs publish-deb triggers.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

debian/lmcp/build-deb.sh

@@ -0,0 +1,58 @@
+#!/bin/bash
+# Build lmcp_<ver>_all.deb from this directory using dpkg-deb directly.
+# Run from inside the runner container, which has dpkg installed.
+#
+# This avoids dh/debhelper to keep the build simple and runnable on a
+# non-Debian builder. The resulting .deb is structurally a normal apt
+# package (Architecture: all, depends on lua + lua-socket).
+set -euo pipefail
+
+PKGVER=0.3.0
+PKGREL=1
+LMCP_TARBALL_SHA256=80a37fc41633ae285b86f2f6cdd97f0c922c03022dce09addd47aeb379f2bcff
+HERE=$(dirname "$(readlink -f "$0")")
+
+work=$(mktemp -d)
+trap "rm -rf $work" EXIT
+
+cd "$work"
+curl -sSLfo lmcp.tar.gz "https://git.reauktion.de/marfrit/lmcp/archive/v${PKGVER}.tar.gz"
+echo "$LMCP_TARBALL_SHA256  lmcp.tar.gz" | sha256sum -c
+tar xzf lmcp.tar.gz
+
+ROOT="$work/pkgroot"
+mkdir -p "$ROOT/DEBIAN" \
+         "$ROOT/usr/share/lua/5.4" \
+         "$ROOT/usr/bin" \
+         "$ROOT/usr/share/doc/lmcp"
+
+cp lmcp/lmcp.lua   "$ROOT/usr/share/lua/5.4/"
+cp lmcp/json.lua   "$ROOT/usr/share/lua/5.4/"
+cp lmcp/server.lua "$ROOT/usr/share/lua/5.4/"
+install -m 755 lmcp/example_server.lua "$ROOT/usr/bin/lmcp-example"
+cp lmcp/README.md  "$ROOT/usr/share/doc/lmcp/"
+cp "$HERE/debian/copyright" "$ROOT/usr/share/doc/lmcp/copyright"
+cp "$HERE/debian/changelog" "$ROOT/usr/share/doc/lmcp/changelog.Debian"
+gzip -9 -n "$ROOT/usr/share/doc/lmcp/changelog.Debian"
+
+cat > "$ROOT/DEBIAN/control" <<EOF
+Package: lmcp
+Version: ${PKGVER}-${PKGREL}
+Section: net
+Priority: optional
+Architecture: all
+Depends: lua5.4 | lua5.3 | lua, lua-socket
+Maintainer: Markus Fritsche <mfritsche@reauktion.de>
+Homepage: https://git.reauktion.de/marfrit/lmcp
+Description: Lightweight MCP server in pure Lua
+ lmcp is a small Model Context Protocol server written in Lua. It exposes
+ user-defined tools over HTTP for use by AI agents.
+ .
+ Library files install to /usr/share/lua/5.4/. The example server is
+ available as /usr/bin/lmcp-example.
+EOF
+
+# Build the .deb. Output to current dir of the caller.
+DEB_OUT=lmcp_${PKGVER}-${PKGREL}_all.deb
+dpkg-deb --root-owner-group --build "$ROOT" "$HERE/$DEB_OUT"
+echo "built: $HERE/$DEB_OUT"