feat(dictionary): characters of Chinese, Korean and Greek, written by hand; pinyin typed

Parity with Japanese's kanji and kana:

- The characters' tab is named by its language (Hanzi, Hangul & Hanja,
  Alphabet), its groups too: HSK levels and the characters in common use
  (Hong Kong's grades for traditional ones); Hangul and the Hanja taught
  in schools; Greek's letters. Radicals for Chinese and Korean in their
  own forms (讠 for 言 in simplified Chinese), none for Greek.
- A character's readings are named as its language names them: On and
  Kun, Pinyin, Eum and Hun (음, 훈); a letter means its sound and name.
- How characters are written comes by language: Chinese from Make Me a
  Hanzi (its medians in KanjiVG's square, Arphic Public License, a data
  file beside the app, never in cards), the Hangul letters drawn by the
  curator; a Korean word is written letter by letter (닭: ㄷ ㅏ ㄺ). Words
  of alphabets (German, Greek) aren't written by hand.
- A Chinese word's pinyin is typed in a session, tone numbers turning
  into marks (ni3 → nǐ); KRDict's levels (초급, 중급, 고급) tag Korean
  words; a Korean word's pronunciation shows in brackets ([가치]).
- Smaller: Look up in the composer keeps a noun's article; the Watch
  filter names its level list; hints and placeholders by language.

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

halkyon_learn_flutter/lib/l10n/app_en.arb

@@ -753,6 +753,25 @@
   "dictionaryCharacterSearchHint": "A kanji or kana, a reading in kana or romaji, or a meaning",
   "dictionaryTabWords": "Words",
   "dictionaryTabCharacters": "Kanji & kana",
+  "dictionaryTabCharactersChinese": "Hanzi",
+  "@dictionaryTabCharactersChinese": {"description": "The tab of Chinese characters in a dictionary of Chinese."},
+  "dictionaryTabCharactersKorean": "Hangul & Hanja",
+  "@dictionaryTabCharactersKorean": {"description": "The tab of Korean letters and Hanja in a dictionary of Korean."},
+  "dictionaryTabCharactersGreek": "Alphabet",
+  "@dictionaryTabCharactersGreek": {"description": "The tab of Greek's letters in a dictionary of Greek."},
+  "dictionaryCharacterSearchHintChinese": "A character, its pinyin, or a meaning",
+  "dictionaryCharacterSearchHintKorean": "A Hanja or Hangul letter, its sound, or a meaning",
+  "dictionaryCharacterSearchHintGreek": "A letter or its name",
+  "dictionaryGroupHsk": "HSK levels",
+  "dictionaryGroupCommonCharacters": "In common use",
+  "dictionaryGroupHongKongGrades": "Hong Kong school grades",
+  "dictionaryGroupHangul": "Hangul",
+  "dictionaryGroupEducationHanja": "Hanja taught in schools",
+  "dictionaryGroupGreek": "Letters",
+  "dictionaryLabelHangul": "Hangul letters",
+  "dictionaryLabelEducationHanja": "1,800 basic Hanja",
+  "dictionaryLabelGreek": "Greek alphabet",
+  "dictionaryLabelCommonCharacters": "3,500 common characters",
   "dictionaryLabelHiragana": "Hiragana",
   "dictionaryLabelKatakana": "Katakana",
   "dictionaryGrade": "Grade {grade}",
@@ -792,9 +811,9 @@
   "kanjiPlayAgain": "Play again",
   "kanjiNoStrokes": "There's no stroke order for this character.",
   "kanjiComponents": "Components",
-  "studySettingsCharacters": "Kanji & kana",
+  "studySettingsCharacters": "Characters",
   "studySettingsWriteByHand": "Write by hand",
-  "studySettingsWriteByHandDescription": "Kanji, kana and words are written stroke by stroke and checked as you go, on a schedule of their own. Words written aren't quizzed or typed.",
+  "studySettingsWriteByHandDescription": "Kanji, hanzi, Hanja, kana, Hangul and words written with them are written stroke by stroke and checked as you go, on a schedule of their own (a Korean word letter by letter). Words written aren't quizzed or typed.",
   "writingHint": "Hint",
   "writingShow": "Show it",
   "writingMistakes": "{count, plural, =0{No mistakes} =1{1 mistake} other{{count} mistakes}}",
@@ -943,6 +962,21 @@
   "characterKunReadingsHint": "Japanese, in hiragana, okurigana after a dot: た.べる",
   "characterOn": "On",
   "characterKun": "Kun",
+  "characterPinyin": "Pinyin",
+  "characterEum": "Eum",
+  "characterHun": "Hun",
+  "characterPinyinReadings": "Pinyin",
+  "characterPinyinReadingsHint": "With tone marks or numbers: shuǐ, shui3",
+  "characterEumReadings": "Sounds (eum)",
+  "characterEumReadingsHint": "Sino-Korean, in Hangul: 수",
+  "characterHunReadings": "Native meanings (hun)",
+  "characterHunReadingsHint": "Korean words for its meaning, in Hangul: 물",
+  "characterPrimaryMeaningHintLetter": "Primary meaning, or a letter's sound",
+  "composerPlaceholderCharacterChinese": "Add a character",
+  "composerPlaceholderCharacterKorean": "Add a Hanja or Hangul letter",
+  "composerPlaceholderCharacterGreek": "Add a letter",
+  "vocabularyReadingHintPinyin": "Pinyin, with tone marks or numbers",
+  "vocabularyReadingHintPronunciation": "Pronunciation, where it differs from the spelling",
   "matchingCategories": "Categories",
   "matchingCategoriesHint": "The drop-zone cards learners drag items onto. Each category needs at least one item, so a card can't have more categories than items.",
   "matchingCategory": "Category {number}",
@@ -1085,8 +1119,9 @@
   "studySettingsQuizMc": "Quiz with multiple choice",
   "studySettingsQuizMcDescription": "Show vocabulary cards as a multiple-choice question, with wrong answers drawn from other vocabulary in this set.",
   "studySettingsTypeReading": "Type the reading",
-  "studySettingsTypeReadingDescription": "Words with kanji ask for their reading, typed in kana; romaji turn into kana as you type.",
+  "studySettingsTypeReadingDescription": "Words with kanji ask for their reading, typed in kana (romaji turn into kana as you type); Chinese words for their pinyin (tone numbers turn into marks: ni3 becomes nǐ).",
   "studyTypedHint": "The reading, in kana or romaji",
+  "studyTypedHintPinyin": "The pinyin, with tone numbers or marks",
   "studyTypedRight": "Right",
   "studyTypedWrong": "You typed {answer}",
   "@studyTypedWrong": {"placeholders": {"answer": {"type": "String"}}},
@@ -1094,7 +1129,7 @@
   "studyAspectReading": "Reading",
   "studyAspectExpression": "Expression",
   "studyAspectMixed": "Mixed",
-  "studySettingsAspectDescription": "What to recall — the meaning, the kana reading, or the expression itself (shown the meaning). Mixed varies meaning and reading per card; cards that can’t be quizzed stay a normal flip.",
+  "studySettingsAspectDescription": "What to recall — the meaning, the reading (kana, pinyin), or the expression itself (shown the meaning). Mixed varies meaning and reading per card; cards that can’t be quizzed stay a normal flip.",
   "studySortOldestFirst": "Oldest first",
   "studySortRandom": "Random",
   "studySortNewestFirst": "Newest first",
@@ -2146,7 +2181,8 @@
   "watchFilterFresh": "New words",
   "watchFilterHeld": "Words in the studyset",
   "watchFilterAll": "All words",
-  "watchFilterNoLevel": "No JLPT level",
+  "watchFilterNoLevel": "No {levels} level",
+  "@watchFilterNoLevel": {"description": "Words a level list (JLPT, HSK, KRDict) leaves out.", "placeholders": {"levels": {"type": "String"}}},
   "watchFilterClass": "Word class",
   "watchFilterEmpty": "No words of this video match the filter.",
   "watchClassNoun": "Nouns",