Fix HIGH priority issues: library exit, unquoted paths, and globs

Fixed multiple HIGH severity issues found by QA scan:

1. Library exit usage (lib/http-attack-analyzer.sh):
   - Changed exit 1 to return 1
   - Libraries should return, not exit (would terminate caller)

2. Unquoted path expansions (9 fixes):
   - cleanup-toolkit-data.sh: Quoted $pattern in ls/rm commands
   - hardware-health-check.sh: Quoted /sys/block/$disk/queue paths
   - plesk-helpers.sh: Quoted /var/qmail/mailnames/$domain path
   - Prevents breakage with paths containing spaces

3. Unquoted globs in rm commands (3 fixes):
   - erase-toolkit-traces.sh: Quoted glob patterns
   - Prevents unintended file deletion from glob expansion

All changes improve robustness and prevent edge case failures.

lib/plesk-helpers.sh

@@ -357,7 +357,7 @@ plesk_list_mailboxes() {
     else
         # Fallback: scan mailnames directory
         [ -d "/var/qmail/mailnames/$domain" ] && \
-            ls -1 /var/qmail/mailnames/$domain/ 2>/dev/null
+            ls -1 "/var/qmail/mailnames/$domain/" 2>/dev/null
     fi
 }