Teach AI terminology before the first prediction - #20

Summary

• add a six-lesson AI 101 runway and course-local glossary
• expose canonical prerequisite vocabulary before tutor-led checkpoints
• add optional prepare/check phases before prediction
• distinguish training, inference, generation, reasoning, and product orchestration
• integrate with the latest local tutor event stream
• update tutor adapters, authoring guidance, PRD, ADR 0013, changelog, status, and learner-study protocol

Verification

• clean latest-master worktree: pnpm check (38 suites / 113 tests)
• pnpm build
• pnpm course:test (20 suites / 61 model tests and 14 starter/reference exercise pairs)
• browser suite on isolated port (18 tests, including prerequisite progression, semantic tutor events, narrow layout, and axe)
• site suite (2 tests)

External evidence

The required consented five-learner study remains pending and is documented as external curriculum-validation evidence; no analytics or fabricated evidence is added.

Supersedes #19 without force-pushing.