Documenter subagent, reviewer handoff contract, asset gate

From the paired Opus and Codex manual-run analyses. DESIGN.md moves to
the end of the flow and into a shipped documenter subagent that derives
the system from the built artifact: a rulebook written before the build
gets defended against reality, and a half-stable DESIGN.md hands the
design-system detector an unstable target that buries the build in
noise and invites laundering. The finish reviewer gains the handoff
that failed three times live: the parent captures desktop and mobile
screenshots and passes paths, the reviewer never attempts to render
and names missing inputs in one line, the parent verifies the
five-section return and respawns once on empty. Fidelity against the
approved comp joins its checks; the card keeps commitment only. The
comp ingredient inventory becomes a written gate with raster-by-default
materials and no gradient-as-texture, comps persist under
.impeccable/mocks, the degraded seed names the sandboxed-exec cause,
and the finish line is explicit: a clean detector pass is not finished.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

skill/scripts/concept-seed.mjs

@@ -458,7 +458,9 @@ ASSIGNED INDEX: ${buildIndex}
   The assignment exists to refuse the model's ranking rut, never to outrank
   the user or the brief. Never expose assignment metadata in user-facing labels.
 No challengers this run: the roll service was unreachable and no local
-catalog exists. A sandboxed shell without network egress is the most common
+catalog exists. A sandboxed exec tool with no network access causes exactly
+this; before accepting degradation, rerun this command once through the
+harness's network-enabled command tool. A sandboxed shell without network egress is the most common
 cause: if this harness can rerun the command with network access granted,
 do that once before proceeding. Otherwise proceed with the grounded
 candidates alone; the assignment