System Refactor, GPU & Terminal Overhaul

- Bug Fixes: Rewrote `install_gaming_bullseye()` in `modules/bullseye/legacy.sh` to use a unified `_checklist` flow (matching Debian 12/13) with automatic i386 architecture detection and driver installation. Fixed greetd "Back" menu crash on Debian 11 by adding version-specific conditional logic in `desktop_display.sh`. Corrected ZRAM text overflow in `zram.sh` using `\n` line breaks for terminal wrapping. Updated Kernel Backports warning message in `debianito.sh` to clarify Bullseye limitations.

- Architecture & Repositories: Refactored Debian 11 repository configuration (`configure_repos_bullseye`) to reuse modern submenus (`_repos_enable_components`, `_branch_migration`), eliminating ~44 lines of hardcoded logic and duplicate source list management. Restricted `non-free-firmware` component availability to Debian 12+ in `modules/repos.sh`. Implemented mandatory `apt autoremove -y` and `apt autoclean` execution immediately after enabling non-free/contrib components (`_repos_enable_components`).

- UI & Menus: Added a new "Communication" menu (Option 4) between Internet and Media Players, featuring Signal, Telegram (with Trixie backports warning), and Hexchat. Moved all terminal emulators from System Tools to the "Customization System" -> Terminals submenu (`modules/extras/terminals/terminals.sh`) with version-specific logic (Alacritty 12+, Blackbox/Ptyxis 13+). Added Joplin installer in Office & Productivity for Debian 12/13 only. Integrated Synaptic into Software Centers menu alongside GNOME and Plasma stores. Unified Essential Pack UI across versions, switching between `fastfetch` (Trixie) and `neofetch` (Bookworm/Bullseye).

- Hardware Drivers: Replaced deprecated `install_gpu_drivers()` in `modules/gpu.sh` with `_install_amd_intel_stack()` and `_install_nvidia_stack()`. Implemented specific logic for Debian 13 (Trixie): Blackwell GPUs now enable the official NVIDIA CUDA repository; Maxwell/Pascal on Backports forces a stable kernel path to ensure driver compatibility. Deprecated `install_nvidia_driver()` in favor of new stack functions while preserving global state variables (`NVIDIA_DRIVER_MODE`).

- Utilities & Cleanup: Added `gdebi` and `bleachbit` to System Tools (GUI-only). Standardized menu headers across 15 files using a centralized `SCROLL_HINT` variable. Ensured VLC installation is conditional on headless status checks in Essential Pack modules.

modules/extras/terminals/terminals.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+# terminals.sh — Terminal emulators
+
+_cat_terminals() {
+    local headless=false
+    _is_headless && headless=true
+    if $headless; then
+        echo "Terminals require a GUI — skipping."
+        return
+    fi
+
+    local -a items=()
+    for t in kitty deepin-terminal gnome-terminal lxterminal mate-terminal \
+             qterminal xfce4-terminal konsole terminator guake cool-retro-term \
+             tilix yakuake terminology rxvt-unicode xterm; do
+        items+=("$t" "" "$(_state "$t")")
+    done
+
+    if [ "$DEBIAN_VERSION" = "12" ] || [ "$DEBIAN_VERSION" = "13" ]; then
+        items+=("alacritty" "" "$(_state alacritty)")
+    fi
+    if [ "$DEBIAN_VERSION" = "13" ]; then
+        items+=("blackbox-terminal" "" "$(_state blackbox-terminal)")
+        items+=("ptyxis"            "" "$(_state ptyxis)")
+    fi
+
+    local item_count=${#items[@]}
+    local lista_alto=$((item_count > TUI_ALTO_LISTA ? TUI_ALTO_LISTA : item_count))
+    local choices
+    choices=$(_checklist "Terminals" "Select terminal emulators${SCROLL_HINT}:" \
+        $TUI_ALTO $TUI_ANCHO $lista_alto "${items[@]}")
+    clear
+    [ -z "$choices" ] && return
+
+    for pkg in $(echo "$choices" | tr -d '"'); do
+        if ! is_installed "$pkg"; then
+            _run_install "$pkg"
+        else
+            echo "$pkg already installed."
+        fi
+    done
+    echo -e "${GREEN}Terminals installed.${NC}"
+}