Fix WORDSPLIT issues in for loops (HIGH priority)

Converted unsafe 'for var in $list' loops to 'while read' loops
to properly handle items with spaces in names.

reference-db.sh (4 fixes):
- Line 172: Database iteration (SHOW DATABASES)
- Line 330: Server alias iteration (space-separated aliases)
- Line 345: Domain iteration (get_user_domains)
- Line 414: WordPress config file paths (find results)

user-manager.sh (4 fixes):
- Line 396: Domain iteration in cPanel log paths
- Line 404: Domain iteration in Plesk log paths
- Line 410: Domain iteration in InterWorx log paths
- Line 632: User iteration (list_all_users)

Pattern changes:
- for item in $list → while IFS= read -r item
- Added [ -z "$item" ] && continue for safety
- Used echo "$list" | while or piped commands directly

This prevents word splitting on spaces in database names,
domain names, file paths, and usernames.

lib/user-manager.sh

@@ -394,7 +394,9 @@ get_user_log_files() {
 
     case "$SYS_CONTROL_PANEL" in
         cpanel)
-            for domain in $domains; do
+            # Iterate safely over domains (handles spaces in domain names)
+            echo "$domains" | while IFS= read -r domain; do
+                [ -z "$domain" ] && continue
                 echo "${SYS_LOG_DIR}/${domain}"
                 echo "${SYS_LOG_DIR}/${domain}-ssl_log"
             done
@@ -402,13 +404,17 @@ get_user_log_files() {
         plesk)
             echo "/var/www/vhosts/${username}/statistics/logs/access_log"
             echo "/var/www/vhosts/${username}/statistics/logs/error_log"
-            for domain in $domains; do
+            # Iterate safely over domains (handles spaces in domain names)
+            echo "$domains" | while IFS= read -r domain; do
+                [ -z "$domain" ] && continue
                 echo "/var/www/vhosts/${domain}/statistics/logs/access_log"
                 echo "/var/www/vhosts/${domain}/statistics/logs/error_log"
             done
             ;;
         interworx)
-            for domain in $domains; do
+            # Iterate safely over domains (handles spaces in domain names)
+            echo "$domains" | while IFS= read -r domain; do
+                [ -z "$domain" ] && continue
                 echo "/home/${username}/var/${domain}/logs/access_log"
                 echo "/home/${username}/var/${domain}/logs/error_log"
             done
@@ -628,9 +634,9 @@ get_database_owner() {
     # Database names are typically: username_dbname
     local prefix=$(echo "$db_name" | cut -d_ -f1)
 
-    # Check if this prefix matches a user
-    local users=$(list_all_users)
-    for user in $users; do
+    # Check if this prefix matches a user (iterate safely over usernames)
+    list_all_users | while IFS= read -r user; do
+        [ -z "$user" ] && continue
         if [ "$user" = "$prefix" ]; then
             echo "$user"
             return 0