Add two durable architecture references grounded in current code:
- minio-rustfs-router-compatibility.md: MinIO cmd/api-router.go (S3
object/bucket) and cmd/admin-router.go (admin /v3, /v4) vs RustFS
implementation status, with per-row landing points and a gaps-only
checklist of still-missing admin endpoints (profiling, healthinfo,
LDAP IDP config, replication diff, MRF, batch, locks, speedtest,
log stream, top, trace).
- minio-file-format-compat.md: xl.meta (meta_ver 3 write, <=3 read,
XL2 magic, rs-vandermonde, HighwayHash256 bitrot, inline data) and
.metadata.bin bucket-metadata interop matrix for the backlog#580
items, plus old-RustFS -> new migration and a phased plan.
Cross-links s3-compatibility-matrix.md and admin-route-action-snapshot.md
and indexes both docs in docs/architecture/README.md.
Refs rustfs/backlog#596rustfs/backlog#603rustfs/backlog#580
Zhengchao An