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/Views/tld-registry/index.twig

@@ -291,7 +291,7 @@
                                         <div class="text-sm font-semibold text-gray-900 dark:text-white">{{ tld.tld }}</div>
                                         {% if tld.registry_url %}
                                         <div class="text-sm text-gray-500 dark:text-slate-400">
-                                            <a href="{{ tld.registry_url }}" target="_blank" class="text-primary hover:text-primary-dark">
+                                            <a href="{{ tld.registry_url|safe_url }}" target="_blank" rel="noopener noreferrer" class="text-primary hover:text-primary-dark">
                                                 <i class="fas fa-external-link-alt mr-1"></i>
                                                 Registry
                                             </a>
@@ -375,7 +375,7 @@
                             <div>
                                 <h3 class="font-semibold text-gray-900 dark:text-white">{{ tld.tld }}</h3>
                                 {% if tld.registry_url %}
-                                <a href="{{ tld.registry_url }}" target="_blank" class="text-xs text-primary hover:text-primary-dark">
+                                <a href="{{ tld.registry_url|safe_url }}" target="_blank" rel="noopener noreferrer" class="text-xs text-primary hover:text-primary-dark">
                                     <i class="fas fa-external-link-alt mr-1"></i>
                                     Registry
                                 </a>