clean TUI core

- Stripped forced-scrollbar hack from _menu and _checklist
- Eliminated TUI_ANCHO_REFORZADO overflow across 9 files
- Removed redundant _inst() function globally
- Added dynamic list height calculation for checklists
- Introduced Desktop & Display menu (Option 12)
- Fixed non-free-firmware false positive in repo detection
- Restored terminal transparency for apt/vainfo output"

modules/gaming/_helpers.sh

@@ -32,6 +32,7 @@ _install_mesa_32bit() {
 
     _run_cmd "Mesa 32-bit" "sudo apt install -y ${install_list[*]}" \
         "Installing Mesa drivers (${#install_list[@]} packages)..."
+    echo -e "${GREEN}Mesa 32-bit libraries installed.${NC}"
 }
 
 apt_cache_exists() {