zram menu refactor, mesa fix & sysinfo ui

- Refactored `install_zram` into a dedicated submenu (`zram_menu`) within `modules/zram.sh`. Split monolithic logic into three distinct operations: `_zram_view`, `_zram_create`, and `_zram_remove`. Enables status verification before installation and safe cleanup. Updated main menu entry in `debianito.sh` to call the new sub-menu.
- Resolved Trixie backports dependency conflicts between `mesa-libgallium` and `mesa-va-drivers` (Mesa 26+). Modified package lists in `_helpers.sh` and `gpu.sh` to exclude `mesa-va-drivers` during backports installs, prioritizing `mesa-vulkan-drivers` for stable Gallium integration.
- Implemented dynamic dimensioning in `_show_sysinfo()`. Calculates optimal width/height based on terminal size (`tput cols`) and content length. Truncates long lines to prevent UI overflow in small terminals, capped at 22-line height.

modules/gpu.sh

@@ -27,7 +27,11 @@ _install_amd_intel_stack() {
             header+="${comp_line}\n\n"
             header+="Choose version:"
             if _confirm_custom "No GPU Detected" "$header" "Backports" "Stable" 14 70; then
-                _run_cmd "Mesa" "sudo apt install -y -t ${DEBIAN_CODENAME}-backports ${mesa_pkgs[*]}" \
+                local _bpo_list=()
+                for _p in "${mesa_pkgs[@]}"; do
+                    [ "$_p" != "mesa-va-drivers" ] && _bpo_list+=("$_p")
+                done
+                _run_cmd "Mesa" "sudo apt install -y -t ${DEBIAN_CODENAME}-backports ${_bpo_list[*]}" \
                     "Installing Mesa from backports..."
             else
                 _run_cmd "Mesa" "sudo apt install -y ${mesa_pkgs[*]}" \