fix(curator): HSK levels by the syllabus's tones; variants find their word

The syllabus's reading is matched with its tones first, so 和 hé gets
HSK 1 and 和 hè doesn't; only where no entry of a word reads it so (the
syllabus marks the tone changes of 一 and 不, 一下 yíxià, CC-CEDICT
doesn't) are the letters alone compared. CC-CEDICT's 2,885 entries that
are only "variant of …" (咊, an old variant of 和) are no entries of
their own any more, which repeated their word in the simplified file,
but written forms of that word, finding it in text and searches.

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/test/fixtures/cedict-sample.txt

@@ -44,3 +44,10 @@
 說 说 [shui4] /to persuade/
 說 说 [shuo1] /to speak; to talk; to say/to explain; to comment/to scold; to tell off/(bound form) theory; doctrine/
 銀行 银行 [yin2 hang2] /bank/CL:家[jia1],個|个[ge4]/
+咊 和 [he2] /old variant of 和[he2]/
+和 和 [He2] /surname He/
+和 和 [he2] /(joining two nouns) and; together with; with (Taiwan pr. [han4])/(math.) sum/to make peace/(sports) to draw; to tie/(bound form) harmonious/(bound form) Japan; Japanese/
+和 和 [he4] /to compose a poem in reply (to sb's poem) using the same rhyme sequence/to join in the singing/to chime in with others/
+和 和 [hu2] /to complete a set in mahjong or playing cards/
+和 和 [huo2] /to combine a powdery substance (flour, plaster etc) with water/Taiwan pr. [huo4]/
+和 和 [huo4] /to mix (ingredients) together/to blend/classifier for rinses of clothes/classifier for boilings of medicinal herbs/