Adds `cargo fmt --check` (stock defaults) to ci.yaml's gate, now that the
tree is rustfmt-clean (commit 41b7e9a). Records that reformat in
.git-blame-ignore-revs so `git blame` skips it. Amends ADR-ci-002 (the
deferred "revisit on main" fmt decision) + the ci ADR index.
Closes#35.
Records the CI/release pipeline as ADR-ci-001 and relocates the nix-flake
ADR from main's ADR-0049 to ADR-ci-002 (content unchanged, history note
added). Both live in docs/ci/adr/ with a README index — a dated,
ci-segmented namespace disjoint from main's integer ADR sequence, the
same split the website subproject uses to avoid cross-branch number
collisions. Drops the ADR-0049 entry from docs/adr/README.
ci-001 covers the runner model, the baked nix CI image, the clippy+test
gate, the static-musl release on tag, trigger hygiene, auth, and scope.
claude@clouddev1