nav: Go straight to inbox on launch, when an account available

Fixes: #516

Author: gnprice

lib/widgets/app.dart

@@ -148,6 +148,7 @@ class ZulipApp extends StatelessWidget {
               MaterialWidgetRoute(page: const ChooseAccountPage()),
               if (initialAccountId != null) ...[
                 HomePage.buildRoute(accountId: initialAccountId),
+                InboxPage.buildRoute(accountId: initialAccountId),
               ],
             ];
           });

test/notifications_test.dart

@@ -12,6 +12,7 @@ import 'package:zulip/model/narrow.dart';
 import 'package:zulip/model/store.dart';
 import 'package:zulip/notifications.dart';
 import 'package:zulip/widgets/app.dart';
+import 'package:zulip/widgets/inbox.dart';
 import 'package:zulip/widgets/message_list.dart';
 import 'package:zulip/widgets/page.dart';
 
@@ -198,6 +199,9 @@ void main() {
           (Subject it) => it.isA<MaterialAccountWidgetRoute>()
             ..accountId.equals(eg.selfAccount.id)
             ..page.isA<HomePage>(),
+          (Subject it) => it.isA<MaterialAccountWidgetRoute>()
+            ..accountId.equals(eg.selfAccount.id)
+            ..page.isA<InboxPage>(),
         ],
       ];
       check(pushedRoutes.take(expected.length)).deepEquals(expected);

test/widgets/app_test.dart

@@ -2,6 +2,7 @@ import 'package:checks/checks.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:zulip/widgets/app.dart';
+import 'package:zulip/widgets/inbox.dart';
 import 'package:zulip/widgets/page.dart';
 
 import '../example_data.dart' as eg;
@@ -31,7 +32,7 @@ void main() {
       ]);
     });
 
-    testWidgets('when have accounts, go to home page for first account', (tester) async {
+    testWidgets('when have accounts, go to inbox for first account', (tester) async {
       addTearDown(testBinding.reset);
 
       // We'll need per-account data for the account that a page will be opened
@@ -44,6 +45,9 @@ void main() {
         (Subject it) => it.isA<MaterialAccountWidgetRoute>()
           ..accountId.equals(eg.selfAccount.id)
           ..page.isA<HomePage>(),
+        (Subject it) => it.isA<MaterialAccountWidgetRoute>()
+          ..accountId.equals(eg.selfAccount.id)
+          ..page.isA<InboxPage>(),
       ]);
     });
   });