FIX: Show malware scanner menu even without installed scanners

FIXED:
- Menu now always displays, even if no scanners are currently installed
- Option 9 'Install all scanners' is now accessible
- User can install scanners directly from menu (no early exit)

CHANGED:
- main() function no longer exits if detect_scanners() fails
- Available scanners array still detected/populated (for 'Available Scanners' header)
- Menu shows which scanners are available, with install option

This restores the expected user experience where option 9 is available.

modules/security/malware-scanner.sh

@@ -2674,9 +2674,9 @@ 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
 }