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_curator/test/kanjidic_test.dart

@@ -0,0 +1,125 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:halkyon_learn_curator/src/sources/kanjidic.dart';
+import 'package:test/test.dart';
+
+void main() {
+  late List<Map<String, Object?>> lines;
+
+  setUpAll(() async {
+    final jlpt = await readKanjiJlpt(
+      File('test/fixtures/kanji-data-sample.json'),
+    );
+    lines = [
+      for (final line in kanjidicDictionary(
+        await File('test/fixtures/kanjidic2-sample.xml').readAsString(),
+        jlpt: jlpt,
+      ))
+        jsonDecode(line) as Map<String, Object?>,
+    ];
+  });
+
+  Map<String, Object?> entry(String character) =>
+      lines.skip(1).firstWhere((line) => line['id'] == character);
+  Map<String, Object?> fields(String character) =>
+      entry(character)['entry']! as Map<String, Object?>;
+
+  test('the header says the file holds characters, and whose they are', () {
+    final header = lines.first;
+    expect(header['source'], 'kanjidic');
+    expect(header['kind'], 'characters');
+    expect(header['sourceVersion'], '2026-282');
+    expect((header['language'], header['glossLanguage']), ('ja', 'en'));
+    expect(header['license'], 'CC-BY-SA-4.0');
+    expect(
+      [
+        for (final credit in header['credits']! as List)
+          (credit as Map)['name'],
+      ],
+      ['KANJIDIC2', 'JLPT kanji lists'],
+    );
+  });
+
+  test('a kanji: its readings, English meanings only, grade, strokes, '
+      'frequency and JLPT level', () {
+    final eat = entry('食');
+    expect(eat['headword'], '食');
+    expect(eat['reading'], isNull);
+    expect(eat['labels'], ['jlpt:n5', 'grade:2', 'radical:184']);
+    expect(fields('食'), {
+      'meanings': ['eat', 'food'],
+      'on': ['ショク', 'ジキ'],
+      'kun': ['く.う', 'く.らう', 'た.べる', 'は.む'],
+      'grade': 2,
+      'strokes': 9,
+      'frequency': 328,
+      'jlpt': 5,
+    });
+    expect(fields('一')['meanings'], isNot(contains('un')));
+  });
+
+  test('a search finds a kanji by its on readings in either kana and in '
+      'romaji, by whole kun readings and by its meanings; the kanji part '
+      'of a kun reading only loosely', () {
+    final eat = entry('食');
+    expect(
+      eat['keys'],
+      containsAll([
+        '食',
+        'ショク',
+        'しょく',
+        'shoku',
+        'たべる',
+        'taberu',
+        'くらう',
+        'eat',
+        'food',
+      ]),
+    );
+    expect(eat['keys'], isNot(contains('た')));
+    expect(eat['looseKeys'], containsAll(['た', 'ta', 'く', 'ku']));
+    // ひと- and ひと.つ: the suffix's dash goes, its kanji part is whole.
+    expect(entry('一')['keys'], containsAll(['ひと', 'ひとつ', 'hitotsu']));
+    expect(entry('一')['looseKeys'], isNot(contains('ひと')));
+  });
+
+  test('levels, grades and radicals label the kanji; level and grade rank '
+      'them: JLPT level, then school grade, then frequency', () {
+    expect(entry('亜')['labels'], ['jlpt:n1', 'grade:secondary', 'radical:7']);
+    // KANJIDIC2's classical radical, not Nelson's.
+    expect(entry('唖')['labels'], ['radical:30']);
+    final ranks = [
+      for (final kanji in ['一', '食', '亜', '唖']) entry(kanji)['rank']! as int,
+    ];
+    expect(ranks, orderedEquals([...ranks]..sort()));
+  });
+
+  test('a character with no Japanese reading and no English meaning is '
+      'left out', () {
+    expect(lines.skip(1).where((line) => line['id'] == '僲'), isEmpty);
+  });
+
+  test('hiragana and katakana follow, the kana table each, before every '
+      'kanji, found by their romaji', () {
+    final kana = [
+      for (final line in lines.skip(1))
+        if ((line['labels']! as List).any(['hiragana', 'katakana'].contains))
+          line,
+    ];
+    expect(kana, hasLength(142));
+    expect(kana.first['id'], 'あ');
+    expect(kana[71]['id'], 'ア');
+    expect(kana.last['id'], 'ポ');
+    expect(entry('ア')['labels'], ['katakana']);
+    expect(entry('ア')['keys'], containsAll(['ア', 'あ', 'a']));
+    expect(fields('ぢ'), {'romaji': 'ji', 'script': 'hiragana'});
+    // を is "wo" in the table, found by "o" too.
+    expect(fields('を')['romaji'], 'wo');
+    expect(entry('を')['keys'], containsAll(['wo', 'o']));
+    final lastKana = kana
+        .map((line) => line['rank']! as int)
+        .reduce((a, b) => a > b ? a : b);
+    expect(entry('食')['rank']! as int, greaterThan(lastKana));
+  });
+}