Add Nextcloud OAuth 2.0 login via laravel/socialite

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Providers/Filament/UserPanelProvider.php

@@ -46,6 +46,22 @@ class UserPanelProvider extends PanelProvider
                 NavigationGroup::make('Ressourcen'),
                 NavigationGroup::make('CRM'),
             ])
+            ->renderHook(
+                PanelsRenderHook::AUTH_LOGIN_FORM_AFTER,
+                fn () => new HtmlString(
+                    '<div class="mt-4">'
+                    . '<div class="relative flex items-center gap-3 py-1">'
+                    . '<div class="h-px flex-1 bg-gray-200 dark:bg-gray-700"></div>'
+                    . '<span class="text-xs text-gray-400 dark:text-gray-500">oder</span>'
+                    . '<div class="h-px flex-1 bg-gray-200 dark:bg-gray-700"></div>'
+                    . '</div>'
+                    . '<a href="' . route('auth.nextcloud') . '" class="mt-3 flex w-full items-center justify-center gap-2 rounded-lg border border-gray-300 bg-white px-4 py-2 text-sm font-medium text-gray-700 shadow-sm transition hover:bg-gray-50 dark:border-gray-600 dark:bg-gray-800 dark:text-gray-300 dark:hover:bg-gray-700">'
+                    . '<svg class="h-4 w-4" viewBox="0 0 50 50" fill="currentColor"><path d="M25 2C12.3 2 2 12.3 2 25s10.3 23 23 23 23-10.3 23-23S37.7 2 25 2zm0 7a7 7 0 110 14 7 7 0 010-14zm0 32c-5.8 0-10.9-2.9-14-7.3.1-4.6 9.3-7.2 14-7.2s13.9 2.5 14 7.2C35.9 38.1 30.8 41 25 41z"/></svg>'
+                    . 'Mit Nextcloud anmelden'
+                    . '</a>'
+                    . '</div>'
+                )
+            )
             ->renderHook(
                 PanelsRenderHook::SIDEBAR_FOOTER,
                 fn () => new HtmlString(