One claim, three stores, one real engine

Before you start

The same eight acme.example users you pulled from the API in module 06 are loaded three ways into one real SQLite engine: a relational `users` table, a `users_doc` table of JSON documents, and a `users_kv` key-value table. You are asked to answer ONE control question — "which users lack MFA?" — in each store, prove you evaluated all eight, then diagnose a SQL-injection break by running a concatenated query against a parameterized one. This console is real SQLite running in your browser — the same engine that ships in your phone. You type SQL; the engine returns real result sets, checked against the engine's own output. Nothing is invented; the result set is the answer key. The eight users are seeded for you; start by reading the relational store.

This exercise loads a heavier engine — a desktop-class browser is recommended.