Fix NVIDIA module version selection and add load diagnostics

iso/builder/build-nvidia-module.sh

@@ -20,12 +20,20 @@ DIST_DIR="$2"
 [ -n "$NVIDIA_VERSION" ] || { echo "usage: $0 <nvidia-version> <dist-dir>"; exit 1; }
 [ -n "$DIST_DIR" ]       || { echo "usage: $0 <nvidia-version> <dist-dir>"; exit 1; }
 
-# Detect kernel version from installed headers
-KVER=$(ls /usr/src/ 2>/dev/null | grep '^linux-headers-' | sed 's/linux-headers-//' | head -1)
+# Detect kernel version from installed headers (pick highest version if multiple).
+detect_kver() {
+    ls /usr/src/ 2>/dev/null \
+        | grep '^linux-headers-' \
+        | sed 's/linux-headers-//' \
+        | sort -V \
+        | tail -1
+}
+
+KVER="$(detect_kver)"
 if [ -z "$KVER" ]; then
     echo "=== installing linux-lts-dev ==="
     apk add --quiet linux-lts-dev
-    KVER=$(ls /usr/src/ | grep '^linux-headers-' | sed 's/linux-headers-//' | head -1)
+    KVER="$(detect_kver)"
 fi
 KDIR="/usr/src/linux-headers-${KVER}"
 echo "=== NVIDIA ${NVIDIA_VERSION} (proprietary) for kernel ${KVER} ==="