Fix menu standards: Replace plain dashes with Unicode separators

Replaced all plain dash separators (---) with Unicode (───) for consistency:

Fixed lib/common-functions.sh (1):
- print_section(): 79 dashes → 79 unicode dashes

Fixed lib/user-manager.sh (4):
- All occurrences: 79 dashes → 79 unicode dashes (replace_all)

Fixed modules/performance/php-optimizer.sh (1):
- Table separator: 104 dashes → 104 unicode dashes

Fixed modules/security/malware-scanner.sh (4):
- All occurrences: 40 dashes → 40 unicode dashes (replace_all)

All 8/8 separator issues resolved. Menus now have consistent Unicode styling.

modules/security/malware-scanner.sh

@@ -854,7 +854,7 @@ done
 
     # Consolidated Scanner Results Table
     echo "SCANNER RESULTS SUMMARY:"
-    echo "----------------------------------------"
+    echo "────────────────────────────────────────"
 
     # ImunifyAV results
     if echo "${AVAILABLE_SCANNERS[*]}" | grep -q "imunify"; then
@@ -879,7 +879,7 @@ done
         printf "%-20s %s\n" "Rootkit Hunter:" "$RKH_COUNT warnings"
     fi
 
-    echo "----------------------------------------"
+    echo "────────────────────────────────────────"
     echo ""
 
     if [ -f "$INFECTED_LIST" ] && [ -s "$INFECTED_LIST" ]; then
@@ -891,9 +891,9 @@ done
         echo ""
 
         # IP Reputation Integration: Flag IPs that uploaded malware
-        echo "----------------------------------------"
+        echo "────────────────────────────────────────"
         echo "Analyzing upload sources..."
-        echo "----------------------------------------"
+        echo "────────────────────────────────────────"
 
         # Correlate infected files with Apache logs to find uploading IPs
         local flagged_ips=0