Select a decoder from the chunk's metadata and return a typed value.
mimetypePatterns constrains the representation. Which type comes back
is the chunk's ;type=, or expectedTag when the caller names one. A
chunk with no type parameter is not underspecified — it holds exactly what
its format describes, and decodes to that.
OptionalexpectedTag: stringAdd one codec; duplicate tag/media-type pairs are rejected.
Install JSON, MessagePack, bytes, Blob, Date, Set, Map, and bigint codecs.
Ordered collection of codecs between application values and A11 chunks.
AsyncNodes use a registry on every typed put/read. Register domain codecs (model messages, audio frames, tool events) before generic defaults when they need a distinct MIME/tag contract. MIME patterns and stable type tags let consumers constrain what they will decode instead of trusting arbitrary peer data.