Improve security, validation, and isolation checks

Add multiple security and validation improvements across the app:

- Prevent session fixation: regenerate session ID on login and after successful 2FA; tighten session cookie params (Secure, HttpOnly, SameSite=Lax).
- Harden installer: add CSRF checks for install/update flows and use PDO::quote when injecting admin credentials into SQL migration to avoid injection; add csrf_field() to installer templates.
- Template hardening: add safe_url and safe_mailto Twig filters, escape tag names for JS, and add rel="noopener noreferrer" to external links to mitigate XSS/opener risks.
- Domain controller: validate referrer to avoid open redirects, enforce user isolation mode when finding/deleting/updating domains and when assigning notification groups (ensures users only affect their own resources).
- Notification groups: verify channel belongs to group before deleting or toggling to prevent unauthorized access.
- ErrorLog: whitelist allowed sort columns to avoid arbitrary column injection in ORDER BY.
- Routes: move the debug whois route to protected/admin area.

These changes collectively reduce attack surface (XSS, open redirect, session fixation, SQL injection) and enforce proper resource isolation and input validation.

app/Models/ErrorLog.php

@@ -247,7 +247,9 @@ class ErrorLog extends Model
         }
 
         $whereClause = !empty($where) ? 'WHERE ' . implode(' AND ', $where) : '';
-        $sortColumn = $filters['sort'];
+
+        $allowedSort = ['error_id', 'error_type', 'error_message', 'is_resolved', 'occurred_at', 'last_occurred_at', 'occurrences'];
+        $sortColumn = in_array($filters['sort'], $allowedSort, true) ? $filters['sort'] : 'last_occurred_at';
         $sortOrder = strtoupper($filters['order']) === 'DESC' ? 'DESC' : 'ASC';
 
         $query = "