The review's remaining functional item: send_sync's body resolves
_encode_json_plain (module global) and self.write_encoded (class attribute) at
call time, so a program rebinding either before the first binding call could
turn a legitimate call into an exception. dispatch now writes the call frame
through def-time bound write_encoded+_encode_json_plain, and the log sink goes
through the bound send; the dispatch rebind test also rebinds those two names
(verified fail-before by reverting to send_sync). The annotation test title
matches its assertion direction, and the note (en + zh) registers the
error-class constructor, dispatch primitives, and dont_inherit mechanisms.
Pairing re-recorded.