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-Process.cppm

@@ -81,7 +81,9 @@ export namespace Crafter::Review::Process {
     // A command run to its end with both outputs captured: stdin from
     // `input`, or /dev/null; both outputs read as they come, so neither can
     // fill its pipe and stall the child. With a timeout the child is killed
-    // when it runs out, and timedOut is set.
+    // when it runs out, and timedOut is set; a supervised command (Supervised)
+    // gets SIGTERM, so the supervisor takes its tree down, and SIGKILL 10 s
+    // later if it is still there.
     struct Captured {
         std::int32_t returnCode = -1;
         std::string out;