LYRW files describe themselves completely

LYRW v2 is the legacy layer-weight bank file: a 24-byte header, bank and segment descriptors, region schemas and an entry table. ADR-0027 keeps this import/interchange layout outside the normative VINDEX3 3.0 graph-container contract. A graph container currently uses tensor-table segments, not .lyrw files. Unknown bank tags are preserved; refusal waits for an operation that needs unsupported semantics.