: [2.19.0] Audit sonorités : yod, e muet, doublons et dico prioritaire enfin cohérents

• 2.19.0 — A systematic audit pass over the Sonorités panel and the underlying rhyme engine,
  triggered by real test cases from Alucard. Several genuine accuracy bugs found and fixed,
  each confirmed by direct testing:
  • Trame phonique: doubled consonants ("addition", "attention", "couronne") were counted
    twice instead of once; a lone "s" between two vowels ("poison", "maison") wasn't recognised
    as [z]; "t" followed by "-tion" (not preceded by s/x) wasn't softened to [s] ("nation",
    "national" — "question"/"gestion" correctly stay [t]); "ill" after a vowel is now recognised
    as the yod glide [j] by default ("fille", "brillant"), with a proper exception list for
    words where it stays a real double L ("ville", "tranquille", "mille"/million-milliard,
    "distiller", "osciller", words ending in "-illaire", words starting with the "ill-" prefix,
    and a few proper nouns/medical terms) — also fixed the "Trame phonique" section not using
    the same stable per-theme colours as Allitérations, an inconsistency from 2.17.0.
  • Allitérations: a word covered by the phonetic dictionary could return a consonant found
    anywhere in its transcription as if it were word-initial (fixed in 2.18.0 for "écrit"-like
    cases); yod [j] is now recognised as a valid initial sound too ("ion", "yeux", "hier"),
    dictionary and spelling-based alike.
  • The rhyme engine itself (used everywhere — rhyme scheme, Rimes tab, quality badges):
    classifieRime now checks the phonetic dictionary first when both words are covered by it,
    falling back to the spelling approximation only when at least one isn't — previously the
    approximation could return a match without the dictionary ever being consulted, even when
    available and correct. Separately, "eille"/"ille" (yod) endings no longer collapse onto
    plain "elle" endings ("abeille" was being treated as a perfect rhyme with "nouvelle") — a
    dedicated key is computed for the yod case, using a marker character that mode assonance's
    core-vowel comparison correctly skips (an early version of this fix accidentally broke
    "fille"/"ville" assonance matching by using a marker that looked like a vowel itself). Also
    fixed: a word's final mute e was being left dangling in the rhyme key when anchoring on the
    vowel before it, making e.g. "vole" and "bol" — the exact same sound, [ɔl], differing only
    in grammatical gender — compare as merely "assonance" instead of a full "rime" unless the
    phonetic dictionary happened to override it.
  • Two remaining known gaps, found along the way but not fixed: verb infinitives in
    "-iller"/"-eiller" (e.g. "travailler") still lose the yod distinction, since an earlier rule
    converts their ending before the yod check can run; and words where the anchor vowel and a
    trailing mute e merge into one written group ("vue" vs "vu") aren't yet reconciled the same
    way "vole"/"bol" now are.