Serialise an ArticleMeta as a stable JSON string with a trailing newline. Keys are emitted in declaration order (insertion-order, matching the interface layout). Determinism guarantee: same input → same bytes.
Article meta record
JSON string ready to be written next to article.md
article.md
Serialise an ArticleMeta as a stable JSON string with a trailing newline. Keys are emitted in declaration order (insertion-order, matching the interface layout). Determinism guarantee: same input → same bytes.