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/gaming.sh

@@ -54,7 +54,7 @@ install_gaming() {
     choices=$(_checklist "Gaming Setup" \
         "Select gaming packages to install${SCROLL_HINT}:" $TUI_ALTO $TUI_ANCHO $TUI_ALTO_LISTA \
         "steam"    "Steam (requires 32-bit support)" ON \
-        "gamemode" "Game performance optimization" ON \
+        "gamemode" "Game performance optimization" OFF \
         "mangohud" "Performance overlay (Vulkan/OpenGL)" ON \
         "goverlay" "MangoHud config GUI" ON \
         "heroic"   "Heroic Launcher (Epic/GOG)" OFF \