Halkyon's shared packages

A pub workspace of the Dart packages Halkyon's apps share: halkyon_ui,
Halkyon's look (the theme, fonts, layout and shared widgets, with texts
in English and German), halkyon_core's low-level primitives and
halkyon_interop's cross-app contracts. Dart 3.13 with LeanCode's lints,
configured once at the root; apps take a package by git, pinned to a
signed commit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

packages/halkyon_ui/test/support/test_app.dart

@@ -0,0 +1,19 @@
+import 'package:halkyon_ui/halkyon_ui.dart';
+import 'package:material_ui/material_ui.dart';
+
+/// [home] in an app as a Halkyon app builds one: the theme, and the
+/// package's texts beside Material's, in [locale].
+Widget testApp(
+  Widget home, {
+  Locale locale = const Locale('en'),
+  Brightness brightness = Brightness.light,
+}) => MaterialApp(
+  theme: appTheme(brightness),
+  locale: locale,
+  localizationsDelegates: const [
+    HalkyonUiLocalizations.delegate,
+    ...GlobalMaterialLocalizations.delegates,
+  ],
+  supportedLocales: HalkyonUiLocalizations.supportedLocales,
+  home: home,
+);