Reader and writer for the versioned .stencilcraft JSON file. The JSON header is {"stencilcraft":{"name":"stencilcraft","version":1}}; the document fields share the top-level object with the header. DocumentFields owns field names, flattening, required fields, version 1 defaults, and omitted optional members. Its values remain JSON so the consuming app owns the domain model, geometry validation, and field-to-model mapping.

The crate does not open files or set a file-size policy. Callers perform bounded file I/O before calling File::read.

craft-stencilcraft-format = { git = "https://github.com/storytold/craft-libs", rev = "<commit>" }

File::read parses JSON, validates the name and exact supported version, reads DocumentFields, and ignores unknown members for version 1 compatibility. File::new and to_json_pretty write the current header and flattened fields. Absent next-shape-id defaults to 1 and absent images defaults to an empty list, matching early version 1 files.

cargo test -p craft-stencilcraft-format covers round-trip wire shape, version 1 defaults, unknown members, wrong and missing headers, unsupported versions, malformed JSON, and missing required fields.