chore: Halkyon Learn moves into apps/learn

Its server, client, app and curator, and the tools that write its
assets (maps, Anki fixtures, icons), as they are; paths are fixed in
the commits that follow.

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

apps/learn/halkyon_learn_flutter/test/feature/about/about_test.dart

@@ -0,0 +1,59 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_learn_flutter/src/feature/about/bloc/about_bloc.dart';
+import 'package:halkyon_learn_flutter/src/feature/about/data/about_repository.dart';
+import 'package:material_ui/material_ui.dart';
+
+import '../../support/fake_about_gateway.dart';
+import '../../support/pump_app.dart';
+import '../../support/test_dependencies.dart';
+
+void main() {
+  group('AboutBloc', () {
+    test('finds where the instance says its source is', () async {
+      final bloc = AboutBloc(AboutRepository(FakeAboutGateway()))
+        ..add(const AboutEventStarted());
+      addTearDown(bloc.close);
+
+      await expectLater(
+        bloc.stream,
+        emits(const AboutStateLoaded('https://example.org/halkyon-learn')),
+      );
+    });
+
+    test('says so when the instance cannot be reached', () async {
+      final gateway = FakeAboutGateway()
+        ..unreachable = Exception('No connection');
+      final bloc = AboutBloc(AboutRepository(gateway))
+        ..add(const AboutEventStarted());
+      addTearDown(bloc.close);
+
+      await expectLater(bloc.stream, emits(const AboutStateUnreachable()));
+    });
+  });
+
+  testWidgets('profile → settings → about shows the licences and the source', (
+    tester,
+  ) async {
+    await pumpApp(tester, testDependencies());
+
+    await openTab(tester, 'Profile');
+    await tester.tap(find.byTooltip('Settings'));
+    await tester.pumpAndSettle();
+    await tester.scrollUntilVisible(
+      find.text('About Halkyon Learn'),
+      200,
+      // The citation preview is selectable, a scroll view of its own.
+      scrollable: find.byType(Scrollable).first,
+    );
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('About Halkyon Learn'));
+    await tester.pumpAndSettle();
+
+    expect(
+      find.textContaining('GNU Affero General Public License'),
+      findsOneWidget,
+    );
+    expect(find.text('https://example.org/halkyon-learn'), findsOneWidget);
+    expect(find.text('View licenses'), findsOneWidget);
+  });
+}