Fifty runnable concept bundles taking a reader from ownership to async/unsafe/FFI, then through serde, tokio, axum and sqlx.
Each is a .rs binary (ground truth, in a Cargo workspace member) + .md guide; every value is printed by the .rs — never hand-computed.
Run any with just run <name>. Plus 26 companion library walkthroughs (axum / fred.rs / sqlx) at the bottom.
Built subagent-per-bundle (max 4/batch) and verified via just sweep — 885 checks, 0 failures, all clippy/rustfmt clean; edition 2024.
Tailwind Play CDN needs internet to style.