Real Algol 68 in the wild uses UPPER stropping (BEGIN, INT, MOD), but
the source TM grammar only matched lowercase. Drop the case sensitivity
on keywords/types/operators so the mode highlights both upper- and
lower-stropped code (and mixed editor-state code).
Also fixed the broken operator rules — \b(?::=)\b can never match
because : and = aren't word characters; replaced with bare-symbol
regexes for the punctuation operators while keeping word boundaries on
the alpha ones (OVER, MOD, AND, OR, NOT).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
8a45f07d5f