feat(tools): add root-password and update-server tools

- add `tools/root-password.sh` to change root password interactively or generate a random one
- add `tools/update-server.sh` to run apt update/upgrade/autoremove/autoclean
- register both tools in `lxs.sh` dispatcher and `tools/index.sh` interactive menu
- document new tools in README.md

tools/index.sh

@@ -60,17 +60,21 @@ menu_tools() {
         echo -e "  ${CYAN}[1]${NC} System Infos"
         echo -e "  ${PURPLE}[2]${NC} Server Benchmark"
         echo -e "  ${YELLOW}[3]${NC} Harden Server"
+        echo -e "  ${GREEN}[4]${NC} Change Root Password"
+        echo -e "  ${CYAN}[5]${NC} Update Server"
         echo -e "  ${RED}[0]${NC} Back"
         echo ""
-        echo -e -n "${BOLD}Choice [0-3]: ${NC}"
+        echo -e -n "${BOLD}Choice [0-5]: ${NC}"
         read -r choice
 
         case $choice in
             1) run_sibling "tools/system-infos.sh" ;;
             2) run_sibling "tools/server-benchmark.sh" ;;
             3) run_sibling "tools/harden.sh" ;;
+            4) run_sibling "tools/root-password.sh" ;;
+            5) run_sibling "tools/update-server.sh" ;;
             0) return ;;
-            *) echo -e "${RED}[✗] Invalid option. Please select 0-3.${NC}"; sleep 1; continue ;;
+            *) echo -e "${RED}[✗] Invalid option. Please select 0-5.${NC}"; sleep 1; continue ;;
         esac
 
         if [ "$choice" != "0" ]; then