Fix get_plesk_user_domains() to have fallback when MySQL fails

Issue: get_plesk_user_domains() only tried MySQL query with no fallback.
When MySQL query failed, it returned nothing, causing 0 domains detected.

Fix: Added fallbacks:
1. Try MySQL query (primary)
2. Use Plesk CLI 'plesk bin site --list' + grep for username
3. Check if /var/www/vhosts/$username directory exists

This should now detect domains for Plesk users even when MySQL query fails.

Testing: Will verify on Plesk server

lib/user-manager.sh

@@ -272,8 +272,23 @@ get_plesk_user_domains() {
     [ -z "$1" ] && return 1
     local username="$1"
 
+    # Try MySQL query first
     if command_exists mysql && [ -f /etc/psa/.psa.shadow ]; then
-        mysql -Ns psa -e "SELECT d.name FROM domains d JOIN sys_users u ON d.id=u.domain_id WHERE u.login='$username'" 2>/dev/null
+        local domains=$(mysql -Ns psa -e "SELECT d.name FROM domains d JOIN sys_users u ON d.id=u.domain_id WHERE u.login='$username'" 2>/dev/null)
+        if [ -n "$domains" ]; then
+            echo "$domains"
+            return 0
+        fi
+    fi
+
+    # Fallback: Use Plesk CLI if available
+    if [ -x "/usr/local/psa/bin/plesk" ]; then
+        /usr/local/psa/bin/plesk bin site --list 2>/dev/null | grep -i "$username" || true
+    fi
+
+    # Last resort: Check if vhosts directory exists for this user
+    if [ -d "/var/www/vhosts/$username" ]; then
+        echo "$username"
     fi
 }