Label canonicalisation and series hashing (spec §5.1).
Keys are sorted, each entry rendered as key=value, and entries are
joined with \x00 separators. The canonical string is hashed with
BLAKE2b truncated to 16 bytes. Deterministic across nodes and restarts.
Summary
Functions
Renders a label map into its canonical string form.
Returns the 16-byte BLAKE2b hash of the canonicalised labels.