Junior foundations: declared scope, not market statistics

Reviewed 2026-09-22. The original working note's survey, speed, duplication, adoption and legal claims lacked claim-level source and applicability records. They are withdrawn in the claim ledger. A current access date does not turn an older experiment into recent evidence; accessibility requirements cannot be generalized to every product and jurisdiction from a slogan.

This guide deliberately teaches two abilities: implement and explain independently, and direct/review AI-assisted changes. Reading generated code does not replace writing it on the independent interview route. The instructional sequence is a concrete contract, a tiny example, baseline code, a counterexample, a revised invariant and runnable checks. That is a curriculum decision subject to learner assessment, not a reported industry-wide shift.

Version-specific technical lessons use official documentation. For example, C12 in the ledger constrains what we say about PostgreSQL heap layout; do not infer that every random UUID primary key physically randomizes table rows. Platform releases, legal applicability and hiring formats should be checked at the point where they change a real decision.