CRITICAL FIX: Sync malware scanner menu fix to production branch

FIXED:
- detect_scanners() no longer blocks menu when scanners aren't installed
- Removed show_scanner_installation_guide() call from detection
- main() no longer exits early if no scanners detected
- Menu always displays with option 9 'Install all scanners'

This syncs the critical menu fix from dev branch (beta) to production (main)
ensuring both branches work correctly.

modules/security/malware-scanner.sh

@@ -91,13 +91,9 @@ detect_scanners() {
         available_scanners+=("rkhunter")
     fi
 
-    if [ ${#available_scanners[@]} -eq 0 ]; then
-        echo -e "${RED}No malware scanners detected!${NC}"
-        echo ""
-        show_scanner_installation_guide
-        return 1
-    fi
-
+    # Note: If no scanners are found, available_scanners array will be empty
+    # Menu option 9 allows installation, so we don't exit here
+    # Just return success to allow menu to display
     return 0
 }
 
@@ -2540,9 +2536,9 @@ generate_client_report() {
 
 # Main execution
 main() {
-    if ! detect_scanners; then
-        exit 1
-    fi
+    # Detect scanners (populate available_scanners array)
+    # Don't exit if none found - menu option 9 allows installation
+    detect_scanners || true
 
     show_scan_menu
 }