thread (regex.ha:55-64) and newmatch (ha:66) land verbatim ahead of
their engine consumers; result_free (ha:1113-1116) and strerror
(ha:1126-1127) complete the exported error/result surface.
delete_thread/add_thread deferred behind #15 (append-through-ptr)
and #17 (deref-spine element reads); is_consuming_inst deferred
behind #19 (>48B tagged by-value call boundary unwired + divergent
callee receive) — noted at the Hare-order site.
Tests are row-table driven: thread_shape reads back both appended
threads against a [2]texp want table (root_capture rows deferred —
every read route is compiler-blocked, #6/#7, probed at HEAD);
newmatch_discriminates drives one row per (void|newmatch|nomem)
member, incl. a nomem-vs-newmatch row; result_free also covers the
zero-header empty result (find()'s ha:915-916 no-match shape).
Byte-id re-verified on the regenerated combined: the pre-existing
FC0 regex.finish hunk is the only divergence.