The PREP sets were loose admin-generated quizzes. They are now study plans: one
per year, split into blocks of 50 numbered "Block 1", "Block 2", plus a
"PREP Mixed" plan of 300 drawn at random across every year. 12 plans, 2,821
questions, applied to production.
Block membership is snapshotted rather than stored as a filter — a plan you are
part-way through must not reshuffle between visits. Re-running the seeder updates
years whose questions changed and leaves the mixed draw alone unless --reshuffle.
Starting a block reuses the learner's existing quiz for it; without that,
reopening a block would create a duplicate test each time and scatter the
attempts across them. Only questions the learner may see are included.
Tests: 113 backend green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PpfzbZ1QTLMeVYxM2kyq8m
