feat(opencode): the OpenCode harness, checked against its goldens

The tool source generated from the schema, the home with its view, the
shared and per-process environments, the permission rules, the commands,
the warm-up under the supervisor, the event stream and the
classification, its patterns as hand-written scanners. The goldens record
the answer for each, a warm-up against a fake opencode included.

A timed-out supervised command now gets SIGTERM, so the supervisor takes
its tree down (SIGKILL 10 s later); any other child gets SIGKILL. :Json
gains DumpCompact.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

interfaces/Crafter.Review.cppm

@@ -28,5 +28,6 @@ export import :Memory;
 export import :Mcp;
 export import :Seats;
 export import :SeatPool;
+export import :OpenCode;
 export import :Freeze;
 export import :Driver;