Update os-release branding to show nullpoint identity

- Add nullpoint branding to /etc/os-release PRETTY_NAME field
- Preserve original OS information as base system reference
- Create backup of original os-release file
- Display updated branding information during installation

post-install.sh

@@ -160,6 +160,21 @@ $BANNER
 MOTD
 fi
 
+# Modify /etc/os-release to show nullpoint branding
+echo "[+] Updating /etc/os-release with nullpoint branding..."
+if [ -f /etc/os-release ]; then
+    # Backup original
+    cp /etc/os-release /etc/os-release.bak
+    
+    # Get original PRETTY_NAME value
+    ORIG_PRETTY_NAME=$(grep '^PRETTY_NAME=' /etc/os-release | cut -d'"' -f2)
+    
+    # Update PRETTY_NAME to show nullpoint with base OS info
+    sed -i "s/^PRETTY_NAME=.*/PRETTY_NAME=\"nullpoint (base: ${ORIG_PRETTY_NAME})\"/" /etc/os-release
+    
+    echo "  - Updated PRETTY_NAME to 'nullpoint (base: ${ORIG_PRETTY_NAME})'"
+fi
+
 # Install additional packages
 echo "[+] Installing additional packages..."
 dnf install -y \