feat: Complete Phase 1 Authentication and setup Flutter project structure

- Completed authentication system with signup, login, password reset, and logout
- Enhanced error handling and accessibility across all auth flows
- Added comprehensive loading states and user feedback
- Implemented confirmation dialogs for destructive actions
- Setup complete Flutter project structure with proper configuration
- Added planning documentation for Phase 2 household creation
- All Phase 1 success criteria verified and complete

windows/flutter/generated_plugin_registrant.cc

@@ -0,0 +1,20 @@
+//
+//  Generated file. Do not edit.
+//
+
+// clang-format off
+
+#include "generated_plugin_registrant.h"
+
+#include <app_links/app_links_plugin_c_api.h>
+#include <flutter_secure_storage_windows/flutter_secure_storage_windows_plugin.h>
+#include <url_launcher_windows/url_launcher_windows.h>
+
+void RegisterPlugins(flutter::PluginRegistry* registry) {
+  AppLinksPluginCApiRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("AppLinksPluginCApi"));
+  FlutterSecureStorageWindowsPluginRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("FlutterSecureStorageWindowsPlugin"));
+  UrlLauncherWindowsRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("UrlLauncherWindows"));
+}