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/css/legal.css

@@ -0,0 +1,19 @@
+body.auth-page {
+    display: block;
+    align-items: unset;
+    justify-content: unset;
+    min-height: 100vh;
+}
+
+body.auth-page .auth-container {
+    max-width: none;
+    width: 100%;
+    padding: 0;
+}
+
+@media (max-width:768px) {
+    .legal-container .legal-card { width: 92% !important; padding: 1.5rem !important; }
+}
+@media (max-width:480px) {
+    .legal-container .legal-card { width: 96% !important; padding: 1rem !important; }
+}