refactor: extract inline CSS/JS from views into separate asset files (20+ files)

Phase A — HTML removed from PHP files:
- RateLimitMiddleware.php: heredoc moved to views/errors/429.php
- public/index.php: inline HTML replaced with View::error()
- AuthMiddleware.php: <script> redirect replaced with <meta refresh>

Phase B — Inline CSS/JS extracted from views:
- CSS: landing.css (459 lines), legal.css (shared by terms+privacy)
- JS: 17 new files extracted from ~20 view files
  - main.js (layout sidebar + notifications)
  - dashboard-chart.js, server-show.js, server-services.js
  - nginx-manager.js, database-manager.js
  - terminal.js, team-show.js, team-index.js
  - server-list.js, server-permissions.js (shared by edit+create)
  - server-ssl.js, server-processes.js, system-users.js
  - admin-users.js, audit-log.js, admin-notifications.js, admin-security.js
  - notifications.js

Total: -3264 lines from views, +288 lines in new assets

views/admin/audit.php

@@ -187,45 +187,4 @@ function selected(string $value, string $compare): string {
     </div>
 </div>
 
-<script>
-function buildQuery() {
-    const params = [];
-    const fields = [
-        { key: 'action', id: 'f_action' },
-        { key: 'username', id: 'f_username' },
-        { key: 'ip_address', id: 'f_ip_address' },
-        { key: 'entity_type', id: 'f_entity_type' },
-        { key: 'details', id: 'f_details' },
-        { key: 'date_from', id: 'f_date_from' },
-        { key: 'date_to', id: 'f_date_to' },
-    ];
-    fields.forEach(function (f) {
-        const el = document.getElementById(f.id);
-        if (el && el.value) {
-            params.push(encodeURIComponent(f.key) + '=' + encodeURIComponent(el.value));
-        }
-    });
-    return params.length ? '/admin/audit?' + params.join('&') : '/admin/audit';
-}
-
-document.addEventListener('change', function (e) {
-    if (e.target.matches('#f_date_from, #f_date_to, #f_action, #f_entity_type')) {
-        window.location.href = buildQuery();
-    }
-});
-
-document.addEventListener('keydown', function (e) {
-    if (e.key === 'Enter' && e.target.matches('#f_username, #f_details, #f_ip_address')) {
-        window.location.href = buildQuery();
-    }
-});
-
-function clearFilters() {
-    window.location.href = '/admin/audit';
-}
-
-function clearField(id) {
-    document.getElementById(id).value = '';
-    window.location.href = buildQuery();
-}
-</script>
+<script src="/assets/js/audit-log.js"></script>