feat(packaging): postinst that enables + starts authforge-daemon

debian/authforge-daemon.postinst

@@ -0,0 +1,18 @@
+#!/bin/sh
+set -e
+
+#DEBHELPER#
+
+case "$1" in
+    configure)
+        if [ -d /run/systemd/system ]; then
+            systemctl daemon-reload || true
+            if [ -z "${DPKG_ROOT:-}" ]; then
+                deb-systemd-helper enable authforge-daemon.service >/dev/null || true
+                deb-systemd-invoke start authforge-daemon.service >/dev/null || true
+            fi
+        fi
+        ;;
+esac
+
+exit 0