feat(curator): Tatoeba's sentences as examples in every new language

JMdict brings Tatoeba's sentences for Japanese; the other languages'
dictionaries had none (CC-CEDICT) or Wiktionary's own, often
quotations. Each file now takes Tatoeba's sentences of the week (its
per-language exports, CC BY 2.0 FR) as its entries' first examples,
which become a card's hints: each sentence with a translation into the
dictionary's meaning language goes to the entries its words find, cut
as the app cuts a line of subtitles (at spaces, Korean's particles off,
Chinese by its longest words), up to three for each, those using the
word as its headword writes it first (Haus rather than zu Hause; 学习
rather than 學習 in the simplified dictionary), then those nearest seven
words long. German's common words nearly all get some (8,849 of
9,292), in ten seconds and under 300 MB; a dictionary whose sentences
can't be had keeps its words. `curate tatoeba` does the same for a file
made by hand.

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/tatoeba-deu-eng_links.tsv

@@ -0,0 +1,10 @@
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+605418	24278
+10051184	8475487
+1107645	1098492
+2205383	2203598
+2491619	1364167
+2491619	5222666
+13139663	13139893
+910906	462934