Add system update feature, git-ignore local configs, and fix homepage request logging

- Exclude config.json and admin.json in .gitignore so live settings/passwords are never overwritten by git
- Auto-generate config.json and admin.json with defaults if missing
- Add config.json.example and admin.json.example reference templates
- Add System Update page (/admin/update) in Admin Console to pull updates via Git with 1 click
- Log effective page name in index.php instead of literal 'auto'
- Add extra HAProxy/PFSense proxy headers to RequestLogger::getClientIp()

admin/templates/layout.php

@@ -86,6 +86,11 @@ $layoutSidebarColor = $layoutThemeConfig['header_color'] ?? '#0a369d';
                     <i class="bi bi-journal-text"></i> Logs
                 </a>
             </li>
+            <li class="nav-item">
+                <a class="nav-link <?= ($route ?? '') === 'update' ? 'active' : '' ?>" href="/admin/update">
+                    <i class="bi bi-cloud-arrow-down"></i> Update
+                </a>
+            </li>
             <li class="nav-item mt-3">
                 <a class="nav-link" href="/" target="_blank">
                     <i class="bi bi-box-arrow-up-right"></i> Website bekijken
@@ -168,6 +173,9 @@ $layoutSidebarColor = $layoutThemeConfig['header_color'] ?? '#0a369d';
             case 'logs':
                 require __DIR__ . '/pages/logs.php';
                 break;
+            case 'update':
+                require __DIR__ . '/pages/update.php';
+                break;
         }
         ?>
     </main>