feat(curator): characters of Chinese and Korean, the Greek alphabet, Korean words from KRDict

For parity with Japanese's KANJIDIC2 and kana:

- Unihan (Unicode License v3) makes characters' dictionaries: the 8,105
  standard simplified characters (unihan-hans) and the traditional ones in
  use (unihan-hant), told apart and ranked by CC-CEDICT's words (Unihan
  calls 这 its own traditional variant; 後 ranks as the 后 of 以后), with
  pinyin, meanings, strokes, Kangxi radical, HSK 2025 character levels,
  the 3,500 common ones and Hong Kong's grades; and Korean Hanja
  (unihan-ko) with their sounds, the 1,800 of education, and their native
  readings from Wiktionary (물 수), with the 40 Hangul letters as kana are.
- The Greek alphabet, the curator's own (CC0): letters with names,
  transliteration and sound.
- KRDict, the Basic Korean Dictionary for learners (CC BY-SA 2.0 KR,
  downloaded without an account), replaces Wiktionary for Korean's words:
  learners' levels, pronunciation where it differs from the spelling
  (같이 [가치]), Hanja, English senses; Wiktionary's update keeps the
  words' forms (가다's 99) and the Hanja's readings beside it for both.
- The update converts KRDict when its page offers another export and the
  characters weekly, and removes the files of languages no longer kept
  or of sources replaced.

Measured on the real data: Unihan 3 s; KRDict 54,870 entries in 24 s
and under 600 MB.

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_curator/data/README.md

@@ -39,3 +39,8 @@ Only each word's level reaches the dictionaries (`hsk:N`), with the pinyin to
 tell CC-CEDICT's readings of one word apart; the curator credits both. The
 Ministry claims copyright on the standard's documents; a word's level is a fact
 about it, which the dictionaries keep with attribution (decided 2026-10-14).
+`hsk/syllabus2025_chars.tsv` lists the syllabus's 3,088 characters to recognise
+(认读字) with their levels (246, 125, 284, 441, 431 and 413 for levels 1 to 6,
+1,148 for 7 to 9), from the same repository and commit (`corpus/syllabus2025/`),
+MIT, unchanged; they label the Chinese characters (`hsk:N`) as the words' label
+the words.