feat(app): kanji and kana in the dictionary, beside the words

Where the instance holds the characters of a studyset's language, the
dictionary screen has a tab for them, Kanji & kana: search by character,
reading (kana or romaji) or meaning, and whole levels to add, under their
names: the kana (hiragana, katakana), the JLPT levels and the school
grades. A character becomes a character card, its meanings (a kana's
romaji) and readings, tagged with its level (JLPT-N5), school grade
(Grade 1 … Grade 6, Secondary school) and script (Hiragana, Katakana). A
character card's Look up searches the characters, and an entry looked up
again on a card swaps the tags the one before brought, as words do.

A dictionary's entries are now words or characters (DictionaryItem), as
its kind says.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMm7usAo6q9ZZRoPkWjoxi
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_flutter/lib/l10n/app_localizations_de.dart

@@ -1868,6 +1868,87 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get dictionaryLookUp => 'Im Wörterbuch nachschlagen';
 
+  @override
+  String get dictionaryCharacterSearchHint =>
+      'Ein Kanji oder Kana, eine Lesung in Kana oder Romaji, oder eine Bedeutung';
+
+  @override
+  String get dictionaryTabWords => 'Wörter';
+
+  @override
+  String get dictionaryTabCharacters => 'Kanji & Kana';
+
+  @override
+  String get dictionaryLabelHiragana => 'Hiragana';
+
+  @override
+  String get dictionaryLabelKatakana => 'Katakana';
+
+  @override
+  String dictionaryGrade(int grade) {
+    return 'Klasse $grade';
+  }
+
+  @override
+  String get dictionaryLabelSecondary => 'Weiterführende Schule';
+
+  @override
+  String get dictionaryGroupKana => 'Kana';
+
+  @override
+  String get dictionaryGroupJlpt => 'JLPT-Stufen';
+
+  @override
+  String get dictionaryGroupGrades => 'Schuljahre';
+
+  @override
+  String dictionaryStrokes(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Striche',
+      one: '1 Strich',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String get dictionaryCharacterLevelsHint =>
+      'Jedes Schriftzeichen einer Stufe wird eine Karteikarte, in der Reihenfolge ihrer Liste, mit Stufe, Schuljahr oder Schrift als Tags. Schriftzeichen, die schon in diesem Lernset sind, werden ausgelassen.';
+
+  @override
+  String dictionaryAddCharacters(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Schriftzeichen hinzufügen',
+      one: '1 Schriftzeichen hinzufügen',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String dictionaryCharactersAdded(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count Schriftzeichen hinzugefügt.',
+      one: '1 Schriftzeichen hinzugefügt.',
+      zero: 'Keine neuen Schriftzeichen.',
+    );
+    return '$_temp0';
+  }
+
+  @override
+  String dictionaryConfirmCharactersTitle(int count) {
+    return '$count Schriftzeichen hinzufügen?';
+  }
+
+  @override
+  String dictionaryCharacterCredits(String sources) {
+    return 'Schriftzeichen aus $sources.';
+  }
+
   @override
   String get aboutDictionaries => 'Wörterbücher dieser Instanz';