nvidia menu & management updates

- Refined `_show_nvidia_version_menu` in `modules/gpu/nvidia.sh` for Debian 12/13 with precise labels ("Newest Stable", "Kepler Support") and explicit official repo recommendations.
- Introduced new standalone module `modules/gpu/nvidia_manage.sh` integrated into the dispatcher to handle driver lifecycle management (Install/Change vs Remove) before version selection.
- Implemented safe removal logic (`_nvidia_remove`) with explicit package purging, explicitly excluding `firmware-misc-nonfree`, and cleaning specific configs/repos without wildcards.
- Ensured idempotency across all steps using `|| true` and preserved user CUDA toolkits while restoring Nouveau via initramfs regeneration.

modules/gpu/nvidia.sh

@@ -195,14 +195,14 @@ _is_cuda_repo_ready() {
 _show_nvidia_version_menu() {
     local choice
     if [ "$DEBIAN_VERSION" = "12" ]; then
-        choice=$(_menu "NVIDIA Driver Version" "Select the NVIDIA driver version for Debian 12 (Bookworm):" 12 70 3 \
-            "535" "Official NVIDIA driver (Recommended)" \
-            "470" "Legacy 470 (Kepler/Tesla GPUs)")
+        choice=$(_menu "Select NVIDIA Driver for Debian 12 (Bookworm):" "Choose the NVIDIA driver version:" 12 70 3 \
+            "535" "v535 — Debian Official (Recommended)" \
+            "470" "v470 — Debian Legacy (Kepler Support)")
     elif [ "$DEBIAN_VERSION" = "13" ]; then
-        choice=$(_menu "NVIDIA Driver Version" "Select the NVIDIA driver version for Debian 13 (Trixie):" 14 70 5 \
-            "550" "Official Debian driver (Recommended)" \
-            "590" "NVIDIA Repo v590 (Turing/Ampere/Ada/Blackwell)" \
-            "595" "NVIDIA Repo v595 (Latest)")
+        choice=$(_menu "Select NVIDIA Driver for Debian 13 (Trixie):" "Choose the NVIDIA driver version:" 14 70 5 \
+            "550" "v550 — Debian Official (Recommended)" \
+            "590" "v590 — NVIDIA CUDA Repo (Production Branch)" \
+            "595" "v595 — NVIDIA CUDA Repo (Newest Stable)")
     else
         NVIDIA_SELECTED_VERSION="auto"
         return 0