* docs(kms): record the cryptographic compliance position
RustFS links no FIPS-validated cryptographic module: the rustls provider is
the ordinary aws-lc-rs build, and every data-path AEAD is RustCrypto. The
crypto crate's default-on `fips` feature only selects PBKDF2+AES-GCM over
Argon2id, with the same RustCrypto implementations behind both branches, so
it cannot support a validation claim either.
Document that status, the terminology rules for external material, the real
semantics of the `fips` feature with a rename direction, the cost of the
three routes to a stronger position, and the sequencing rules for retiring an
algorithm.
Refs rustfs/backlog#1587 (part of rustfs/backlog#1562)
* docs(kms): document the mixed-version cluster constraints
Collect the cross-version constraints that landed with versioned rotation and
the check-and-set lifecycle work: which persisted formats decode both ways,
which guarantees only hold once every node is upgraded, how long nodes can
disagree on lifecycle state, and that reconfigure is persisted cluster-wide
but applied only on the node that handled it.
Adds the recommended rolling-upgrade sequence and the list of operations to
avoid while two builds are running.
Refs rustfs/backlog#1581 (part of rustfs/backlog#1562)