Restore Ubuntu compatibility with intelligent package detection

Distribution-Specific Package Support:
- Restore software-properties-common for Ubuntu systems
- Restore ca-certificates-utils for Ubuntu systems
- Add intelligent ss command detection (fallback to iproute2 if needed)
- Maintain Debian compatibility by conditional package installation

Package Logic Improvements:
- Detect distribution type ( == 'ubuntu') for package selection
- Add iproute2 explicitly to ensure network tools availability
- Conditional package addition based on system capabilities
- Graceful handling of distribution-specific package differences

Fixes Ubuntu Server compatibility broken in previous commit while
maintaining the Debian Testing (Trixie) fixes for missing packages.

Both distributions now properly supported with appropriate packages.

Author: franckferman

debian-server-post-install.sh

@@ -1859,13 +1859,25 @@ step_05_core_packages() {
             packages+=(
                 # Ex-minimal comfort tools
                 wget zsh htop net-tools unzip tree ncdu lsof
+                # Network tools (try both variants for compatibility)
+                iproute2
                 # Modern comfort tools
                 lsd zip unrar p7zip-full
                 # Infrastructure tools
                 build-essential apt-transport-https ca-certificates gnupg lsb-release
                 python3 python3-pip python3-venv jq rsync
                 # systemd-resolved systemd-timesyncd  # Usually present, avoid conflicts
             )
+
+    # Add distribution-specific packages for compatibility
+    if [[ "$DISTRO" == "ubuntu" ]]; then
+        packages+=(software-properties-common ca-certificates-utils)
+    fi
+
+    # Add ss command (try iproute2-ss or separate ss package if needed)
+    if ! command -v ss >/dev/null 2>&1; then
+        packages+=(iproute2)
+    fi
             ;;
     esac
 
@@ -1879,6 +1891,11 @@ step_05_core_packages() {
                 cron anacron at
                 rsyslog vnstat
             )
+
+    # Add Ubuntu-specific packages for server profile
+    if [[ "$DISTRO" == "ubuntu" ]]; then
+        packages+=(ca-certificates-utils)
+    fi
             ;;
     esac