Eleven empty crates per DESIGN.md §11, versions and lints pinned once in the
root manifest, Justfile carrying the §12 gate, nix dev shell.
The frontend steps in `just ci` no-op until web/ exists. arr-core carries one
placeholder test because `cargo nextest` fails a zero-test run, and relaxing
that would let a broken filter go green later.
Closes#1
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude