feat(ui): unify child surfaces and show web task creation in a modal (#1633)

ui/flutter/lib/features/home/presentation/pages/home_page.dart

@@ -11,7 +11,7 @@ import '../../../../app/application/app_runtime_controller.dart';
 import '../../../../core/capabilities/app_capabilities.dart';
 import '../../../../core/utils/breakpoints.dart';
 import '../../../../core/utils/file_explorer.dart';
-import '../../../../core/window/app_window_launcher.dart';
+import '../../../../app/router/app_router.dart';
 import '../../../../core/window/app_window_chrome.dart';
 import '../../../../shared/theme/app_design_tokens.dart';
 import '../../../../shared/theme/app_palette.dart';
@@ -580,19 +580,7 @@ class _HomePageState extends ConsumerState<HomePage> {
     }
   }
 
-  void _handleAddTask() {
-    if (!Util.isDesktop()) {
-      context.go('/create');
-      return;
-    }
-    unawaited(
-      AppWindowLauncher.openCreateTaskWindow().then((opened) {
-        if (!opened && mounted) {
-          context.go('/create');
-        }
-      }),
-    );
-  }
+  void _handleAddTask() => unawaited(AppRouter.openCreateTask());
 
   Future<void> _runTaskAction(Future<void> Function() action) async {
     try {

ui/flutter/lib/features/home/presentation/widgets/primary_rail.dart

@@ -1,5 +1,4 @@
-import 'package:flutter/material.dart' show Icons;
-import 'package:flutter/widgets.dart';
+import 'package:shadcn_flutter/shadcn_flutter.dart';
 import 'package:go_router/go_router.dart';
 
 import '../../../../core/window/app_window_chrome.dart';
@@ -28,7 +27,21 @@ class PrimaryRail extends StatelessWidget {
         children: [
           SizedBox(
             height: AppDesignTokens.contentHeaderHeight,
-            child: const Center(child: GopeedAppMark(key: ValueKey('primary-rail-app-mark'))),
+            child: Center(
+              child: AppTooltip(
+                message: context.l10n.task,
+                child: Semantics(
+                  label: context.l10n.task,
+                  button: true,
+                  child: GhostButton(
+                    key: const ValueKey('primary-rail-home-button'),
+                    density: ButtonDensity.icon,
+                    onPressed: () => context.go('/'),
+                    child: const ExcludeSemantics(child: GopeedAppMark(key: ValueKey('primary-rail-app-mark'))),
+                  ),
+                ),
+              ),
+            ),
           ),
           const SizedBox(height: AppDesignTokens.space8),
           _RailItem(

ui/flutter/lib/features/tasks/presentation/pages/create_task_window_page.dart

@@ -44,10 +44,12 @@ import '../widgets/create_task_action_buttons.dart';
 import '../widgets/resolve_download_dialog.dart';
 
 class CreateTaskWindowPage extends ConsumerStatefulWidget {
-  const CreateTaskWindowPage({super.key, this.windowController, this.initialTask});
+  const CreateTaskWindowPage({super.key, this.windowController, this.initialTask, this.onClose, this.modal = false});
 
   final multi_window.WindowController? windowController;
   final CreateTask? initialTask;
+  final ValueChanged<bool>? onClose;
+  final bool modal;
 
   @override
   ConsumerState<CreateTaskWindowPage> createState() => _CreateTaskWindowPageState();
@@ -133,7 +135,7 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
       if (widget.initialTask == null) {
         ref.read(pendingCreateTaskProvider.notifier).clear();
       }
-      if (widget.windowController == null && widget.initialTask == null) {
+      if (widget.windowController == null) {
         // Navigating to /create again reuses this page, so consume subsequent
         // browser/share requests as well as the initial pending task.
         ref.listenManual(pendingCreateTaskProvider, (_, next) {
@@ -371,7 +373,9 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
       child: Padding(
         key: const ValueKey('create-task-safe-content'),
         padding: EdgeInsets.only(
-          top: AppWindowChrome.reservesHeaderInset
+          top: widget.modal
+              ? 0
+              : AppWindowChrome.reservesHeaderInset
               ? AppDesignTokens.windowHeaderHeight
               : MediaQuery.paddingOf(context).top,
         ),
@@ -867,6 +871,10 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
   }
 
   Future<void> _closeWindow() async {
+    if (widget.onClose != null) {
+      widget.onClose!(false);
+      return;
+    }
     if (widget.windowController == null && mounted) {
       context.go('/');
       return;
@@ -888,6 +896,10 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
       }
     }
     if (!mounted || session != _createSession) return;
+    if (widget.onClose != null) {
+      widget.onClose!(true);
+      return;
+    }
     if (widget.windowController != null) {
       // Navigation is best-effort after a successful submission. A navigation
       // failure must not leave a completed form available for resubmission.