amd gcn legacy support & kernel overhaul

- Fixed Mesa 32-bit dependency conflicts by removing mesa-va-drivers from gaming setup; mesa-libgallium now includes VA-API for Mesa >= 25.3.3, resolving solver errors with backports (Mesa 26.x).
- Removed corectrl detection and installation from AMD tools in gpu/amd_intel.sh (retained in System Tools checklist only).
- Added zutty terminal emulator option alongside alacritty for Debian 12+ in terminals.sh.
- Overhauled Kernel menu: replaced "Backports Kernel" with "Kernel" submenu offering Stable, RT, Cloud, and Backports options; removed hardcoded Debian 11 restriction (backports hidden only on Bullseye); headers now installed automatically with all kernel variants; NVIDIA warnings added for Backports (DKMS required) and RT (driver compatibility note).
- Implemented AMD GCN legacy driver migration: is_amd_legacy_gcn() function detects GCN 1.0/1.1 GPUs via whitelist of 85 PCI IDs; offers user prompt to force amdgpu module with GRUB parameters (radeon.si_support=0, radeon.cik_support=0, amdgpu.si_support=1, amdgpu.cik_support=1); safe sed-based injection into GRUB_CMDLINE_LINUX_DEFAULT with backup and idempotency check.
- Standardized UI across 27 checklist locations: unified text to "Check [*] the packages you want installed/updated on your system."; removed SCROLL_HINT variable entirely from all code; changed OK button to "Apply" in _checklist() and _inputbox() only (not in _msg/_menu).
- Reordered gaming menu checklists: i386 moved to top position, steam/mangohud positioned immediately after for better dependency flow.
- Enhanced kernel installation prompts: all variants (Stable, RT, Cloud, Backports) now display candidate version numbers in parentheses using apt-cache policy and madison queries.
- update readme

modules/gpu/amd_intel.sh

@@ -11,13 +11,6 @@ install_amd_firmware() {
 
 offer_amd_tools() {
     local amd_tools=("radeontop")
-    local corectrl_available=false
-
-    if [ "$DEBIAN_CODENAME" = "trixie" ]; then
-        corectrl_available=true
-    elif [ "$(is_backports_enabled)" = "true" ] && apt-cache madison corectrl 2>/dev/null | grep -q "bookworm-backports"; then
-        corectrl_available=true
-    fi
 
     local pkgs
     if [ "$DEBIAN_VERSION" = "11" ]; then
@@ -25,13 +18,8 @@ offer_amd_tools() {
     else
         pkgs=$(pkg_versions "${amd_tools[@]}" nvtop vainfo)
     fi
-    if $corectrl_available; then
-        local ctrl_ver
-        ctrl_ver=$(apt-cache policy corectrl 2>/dev/null | awk 'NR==3 {print $2; exit}')
-        pkgs+="  - corectrl  ${ctrl_ver}\n"
-    fi
 
-    if ! _confirm "AMD Tools" "Install AMD monitoring and control tools?\n\n${pkgs}"; then
+    if ! _confirm "AMD Tools" "Install AMD monitoring tools?\n\n${pkgs}"; then
         echo "Skipping AMD tools."
         return
     fi
@@ -44,14 +32,6 @@ offer_amd_tools() {
     vainfo
     _pause "vainfo output shown above."
 
-    if $corectrl_available; then
-        if [ "$DEBIAN_CODENAME" = "trixie" ]; then
-            _run_cmd "corectrl" "sudo apt install -y corectrl" "Installing corectrl..."
-        else
-            _run_cmd "corectrl" "sudo apt install -y -t ${DEBIAN_CODENAME}-backports corectrl" "Installing corectrl from backports..."
-        fi
-    fi
-
     echo -e "${GREEN}AMD tools installed.${NC}"
 }