Fix NULL check issues (5 HIGH issues resolved)

Added proper null/empty checks and variable quoting in 3 files:

1. wordpress-cron-manager.sh (2 issues):
   - Added validation for $site_path before use
   - Quoted variable in cron command to prevent word splitting
   - Lines 446-449: Check if path is empty or invalid before processing

2. malware-scanner.sh (1 issue):
   - Added safety check for $SCAN_DIR before suggesting rm -rf command
   - Prevents dangerous rm operations if variable is empty or root
   - Line 1583-1585: Guard against accidental deletions

3. mysql-restore-to-sql.sh (2 issues):
   - Quoted $datadir in echo statements showing manual commands
   - Lines 426, 441, 444, 447: Proper quoting in examples

Impact: Prevents potential issues from empty/undefined variables

modules/website/wordpress/wordpress-cron-manager.sh

@@ -442,6 +442,12 @@ case "$choice" in
             count=$((count + 1))
             site_path=$(dirname "$wp_config")
 
+            # Validate site path
+            if [ -z "$site_path" ] || [ ! -d "$site_path" ]; then
+                echo -e "${YELLOW}Warning: Invalid site path${NC}"
+                continue
+            fi
+
             echo -e "${BOLD}Site $count:${NC} $site_path"
 
             # Backup
@@ -458,7 +464,7 @@ case "$choice" in
             fi
 
             # Add cron job with staggered timing
-            cron_cmd="cd $site_path && /usr/bin/php -q wp-cron.php >/dev/null 2>&1"
+            cron_cmd="cd \"$site_path\" && /usr/bin/php -q wp-cron.php >/dev/null 2>&1"
 
             if ! crontab -u "$target_user" -l 2>/dev/null | grep -q "$site_path.*wp-cron.php"; then
                 cron_time=$(generate_staggered_cron)
@@ -545,7 +551,7 @@ case "$choice" in
             fi
 
             # Add cron job with staggered timing
-            cron_cmd="cd $site_path && /usr/bin/php -q wp-cron.php >/dev/null 2>&1"
+            cron_cmd="cd \"$site_path\" && /usr/bin/php -q wp-cron.php >/dev/null 2>&1"
 
             if ! crontab -u "$user" -l 2>/dev/null | grep -q "$site_path.*wp-cron.php"; then
                 cron_time=$(generate_staggered_cron)