fix: homeserver error text not visible in app bar

Signed-off-by: TheOneWithTheBraid <the-one@with-the-braid.cf>

lib/pages/homeserver_picker/homeserver_app_bar.dart

@@ -0,0 +1,37 @@
+import 'package:flutter/material.dart';
+
+import 'package:flutter_gen/gen_l10n/l10n.dart';
+
+import 'package:fluffychat/config/app_config.dart';
+import 'homeserver_picker.dart';
+
+class HomeserverAppBar extends StatelessWidget {
+  final HomeserverPickerController controller;
+
+  const HomeserverAppBar({Key? key, required this.controller})
+      : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return TextField(
+      focusNode: controller.homeserverFocusNode,
+      controller: controller.homeserverController,
+      onChanged: controller.onChanged,
+      decoration: InputDecoration(
+        prefixIcon: Navigator.of(context).canPop()
+            ? IconButton(
+                onPressed: Navigator.of(context).pop,
+                icon: const Icon(Icons.arrow_back),
+              )
+            : null,
+        prefixText: '${L10n.of(context)!.homeserver}: ',
+        hintText: L10n.of(context)!.enterYourHomeserver,
+        suffixIcon: const Icon(Icons.search),
+        errorText: controller.error,
+      ),
+      readOnly: !AppConfig.allowOtherHomeservers,
+      onSubmitted: (_) => controller.checkHomeserverAction(),
+      autocorrect: false,
+    );
+  }
+}

lib/pages/homeserver_picker/homeserver_picker_view.dart

@@ -5,6 +5,7 @@ import 'package:url_launcher/url_launcher.dart';
 
 import 'package:fluffychat/config/app_config.dart';
 import 'package:fluffychat/widgets/layouts/login_scaffold.dart';
+import 'homeserver_app_bar.dart';
 import 'homeserver_picker.dart';
 
 class HomeserverPickerView extends StatelessWidget {
@@ -16,28 +17,9 @@ class HomeserverPickerView extends StatelessWidget {
   Widget build(BuildContext context) {
     final benchmarkResults = controller.benchmarkResults;
     return LoginScaffold(
-      appBar: AppBar(
-        titleSpacing: 0,
-        title: Padding(
-          padding: const EdgeInsets.all(12.0),
-          child: TextField(
-            focusNode: controller.homeserverFocusNode,
-            controller: controller.homeserverController,
-            onChanged: controller.onChanged,
-            decoration: InputDecoration(
-              prefixText: '${L10n.of(context)!.homeserver}: ',
-              hintText: L10n.of(context)!.enterYourHomeserver,
-              suffixIcon: const Icon(Icons.search),
-              errorText: controller.error,
-            ),
-            readOnly: !AppConfig.allowOtherHomeservers,
-            onSubmitted: (_) => controller.checkHomeserverAction(),
-            autocorrect: false,
-          ),
-        ),
-      ),
       body: Column(
         children: [
+          HomeserverAppBar(controller: controller),
           // display a prominent banner to import session for TOR browser
           // users. This feature is just some UX sugar as TOR users are
           // usually forced to logout as TOR browser is non-persistent