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_sentences.tsv

@@ -0,0 +1,10 @@
+1550095	deu	Na, altes Haus!
+9984782	deu	Er ist im Haus.
+605418	deu	Das Haus brennt.
+10051184	deu	Er aß.
+1107645	deu	Ich aß.
+2205383	deu	Wer aß?
+2491619	deu	In welcher Straße?
+13139663	deu	Das ist die Straße.
+910906	deu	Die Straße ist nass.
+345389	deu	Während meiner Abwesenheit wurde in meinem Haus eingebrochen.