- src/lib/random.js: Fisher–Yates shuffle/sample/pickInt; replace every
biased .sort(() => 0.5 - Math.random()) site in testService.
- testService: debias correctIndex via prompt + runtime re-roll (up to 2x
when one position holds >50%); quality gate rejecting <4 distinct
options, banned filler ("all of the above" etc) and explanations
shorter than 20 chars; dedup new questions against the existing bank
via normalised question text.
- Quiz schema/tool/prompt require difficulty ('easy'|'medium'|'hard');
db.getQuizBank defaults legacy records to 'medium' on read.
- learningService.generateCustomTopic: kebab-case slug ID from the
polished label with collision suffixes; default learning_relevance
'standard' when the model omits it.
- Tests for random helpers, dedup/quality-gate behaviour and the
extended quiz schema.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>