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/extras/office/office.sh

@@ -70,8 +70,10 @@ _cat_office() {
         )
     fi
 
+    local item_count=${#items[@]}
+    local lista_alto=$((item_count > TUI_ALTO_LISTA ? TUI_ALTO_LISTA : item_count))
     local choices
-    choices=$(_checklist "Office & Productivity" "Select office applications${SCROLL_HINT}:" $TUI_ALTO $TUI_ANCHO $TUI_ALTO_LISTA \
+    choices=$(_checklist "Office & Productivity" "Select office applications${SCROLL_HINT}:" $TUI_ALTO $TUI_ANCHO $lista_alto \
         "${items[@]}" \
         )