start adding login flow

lib/helpers/extension_helper.dart

@@ -123,9 +123,13 @@ extension ToMessage on Event {
 
 extension ToTheme on ColorScheme {
   ThemeData get theme => ThemeData.from(colorScheme: this).copyWith(
+    cardTheme: CardThemeData(color: primaryContainer),
     appBarTheme: AppBarTheme(
       titleSpacing: 0,
       backgroundColor: surfaceContainerLow,
     ),
+    inputDecorationTheme: const InputDecorationTheme(
+      border: OutlineInputBorder(),
+    ),
   );
 }

lib/helpers/homeserver_helper.dart

@@ -0,0 +1,19 @@
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:nexus/controllers/client_controller.dart";
+
+class HomeserverHelper {
+  final Ref ref;
+  HomeserverHelper(this.ref);
+
+  Future<bool> setHomeserver(Uri homeserverUrl) async {
+    final client = await ref.watch(ClientController.provider.future);
+    try {
+      await client.checkHomeserver(homeserverUrl);
+      return true;
+    } catch (_) {
+      return false;
+    }
+  }
+
+  static final provider = Provider<HomeserverHelper>(HomeserverHelper.new);
+}