test: one owner per case id, a structural devex 0B setup rule, and correct design/gbrain actors

- plan-design-review-plan-mode was registered by two files; the PTY smoke is
  now plan-design-review-plan-mode-smoke, and a registry test requires one
  owner per case in case-sharded files.
- plan-devex-finding-floor: the template's 0B narrative-confirmation question
  is classified as setup structurally instead of timing out a Haiku assessor.
- setup-gbrain-remote: the actor accepted 'skip' on the MCP-registration
  question the test asserts; it now accepts that question and declines others.
- design-review-plugin-handoff: the fake engine cited a file absent from the
  fixture repo and index.html linked a missing styles.css.
Captured-question regressions with negative controls; each case passed a
focused paid run.

test/helpers/setup-gbrain-sandbox.ts

@@ -36,6 +36,19 @@ export function redactPublicValue(value: unknown, token: string, unsafe = () =>
   return value;
 }
 
+/**
+ * Path 4 remote actor: the prompt directs Step 5a registration (the contract under
+ * test), so the MCP-registration question takes its register/recommended option.
+ * Every other gate (privacy, artifacts repo, per-remote policy) is declined or skipped.
+ */
+export function setupGbrainRemoteAnswer(q: { question: string; header?: string; options: Array<{ label: string }> }): string {
+  if (/typed tool surface|\bregister(?:s|ing)?\b[^?]*\bMCP\b|\bMCP\b[^?]*\bregist/i.test(`${q.header ?? ''}\n${q.question}`)) {
+    const accept = q.options.find(o => /^(?:yes|register)\b/i.test(o.label)) ?? q.options.find(o => /\(recommended\)/i.test(o.label));
+    if (accept) return accept.label;
+  }
+  return (q.options.find(o => /skip|decline|no thanks|local/i.test(o.label)) ?? q.options[q.options.length - 1]!).label;
+}
+
 /** Retain the prior Path 4 public projection; SDK private fields are never read. */
 export function publicEvents(events: readonly unknown[]): unknown[] {
   return events.flatMap((event: any) => {