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

public/assets/js/server-list.js

@@ -0,0 +1,30 @@
+function deleteServer(id, name) {
+    if (confirm('Are you sure you want to delete server "' + name + '"?\nThis action cannot be undone.')) {
+        const form = document.createElement('form');
+        form.method = 'POST';
+        form.action = '/servers/' + id + '/delete';
+        const csrf = document.createElement('input');
+        csrf.type = 'hidden';
+        csrf.name = '_csrf_token';
+        csrf.value = document.querySelector('meta[name="csrf-token"]')?.content || '';
+        form.appendChild(csrf);
+        document.body.appendChild(form);
+        form.submit();
+    }
+}
+
+document.getElementById('serverSearch')?.addEventListener('input', function(e) {
+    applyFilters();
+});
+
+document.getElementById('statusFilter')?.addEventListener('change', applyFilters);
+document.getElementById('groupFilter')?.addEventListener('change', applyFilters);
+
+function applyFilters() {
+    const search = document.getElementById('serverSearch')?.value || '';
+    const status = document.getElementById('statusFilter')?.value || '';
+    const group = document.getElementById('groupFilter')?.value || '';
+    window.location.href = '/servers?search=' + encodeURIComponent(search) +
+                           '&status=' + encodeURIComponent(status) +
+                           '&group=' + encodeURIComponent(group);
+}