Steward 0.1.0 (in development): a DHCPv4 server with a web UI, API and CLI

Subnets served per interface, pools, reservations, options at three
levels, leases in SQLite saved before the ACK, ping and decline conflict
checks, validated changes with history and undo, users and tokens, an
audit log, a Kea importer, a sandboxed systemd unit and Debian packages.
Tested with real udhcpc and dhcpcd clients in Docker (scripts/e2e.sh).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

deploy/debian/prerm

@@ -0,0 +1,16 @@
+#!/bin/sh
+# Steward: runs before the package's files are removed (also on upgrades).
+set -e
+
+# On removal (not on upgrade) stop stewardd and the backup timer and remove
+# stewardd's boot-time link (postrm deals with the timer's). Clients keep
+# their addresses until their leases run out.
+if [ "$1" = remove ] && [ -d /run/systemd/system ]; then
+	systemctl stop steward.service steward-backup.timer steward-backup.service 2>/dev/null || true
+	systemctl disable steward.service 2>/dev/null || true
+	if ! command -v deb-systemd-helper >/dev/null 2>&1; then
+		systemctl disable steward-backup.timer 2>/dev/null || true
+	fi
+fi
+
+exit 0