Ctrl/Alt+arrows and double-click treated a run of Thai (Lao, Khmer,
Myanmar) without spaces as one word, and stopped at a word's tone and
vowel marks, which didn't count as part of a word. They now stop at the
word boundaries the line segmenter finds in those scripts (shared with
line breaking, so no more data ships), and combining marks count as
part of a word, also for combining accents in other scripts.
Co-Authored-By: Claude Opus 5.5 <[email protected]>