estrai feat_add_lsb_release in file dedicato e migliora rilevamento distro

- nuovo featlib/lsb-release.sh con feat_add_lsb_release
- docker.sh importa lsb-release.sh
- logica robusta per DISTRIB_ID/DISTRIB_CODENAME con fallback multipli
- case-insensitive per LinuxMint/Ubuntu
- lsb-release installato on-demand solo se necessario

featlib/lsb-release.sh

@@ -0,0 +1,17 @@
+#! /bin/bash --
+[ ! -z "${GREZZO_1737747200}" ] && return; GREZZO_1737747200=0
+
+function feat_add_lsb_release() {
+	if ! feat_missing "apt-get"; then
+		sudo apt-get update
+		sudo apt-get install -y lsb-release
+	elif ! feat_missing "pacman"; then
+		sudo pacman -S --needed lsb-release
+	elif ! feat_missing "apk"; then
+		sudo apk add --no-cache lsb-release
+	elif ! feat_missing "yum"; then
+		sudo yum install -y redhat-lsb-core
+	elif ! feat_missing "zypper"; then
+		sudo zypper in lsb-release
+	fi
+}