pub fn encode_sparse_row_json(
table: &TableSchema,
row_id: &str,
values: &Map<String, Value>,
encryption: &EncryptionConfig,
fallback: Option<&Row>,
) -> Result<Vec<u8>, String>Expand description
Encode one SPARSE push payload (§2.4, §6.1): the keys of values ARE the
presence set — a column with no key stays absent. §5.11: only present
encrypted columns are encrypted, and key resolution runs only then;
absent selector slots fall back to fallback (the stored local row).
Serialized with the wire_columns table.