Initial import from garrytan/gstack@026751e (main snapshot via local relay)

Source: https://github.com/garrytan/gstack/commit/026751e

test/skill-e2e-plan-design-plan-mode.test.ts

@@ -0,0 +1,40 @@
+/**
+ * plan-design-review plan-mode smoke (gate, paid, real-PTY).
+ *
+ * See test/skill-e2e-plan-ceo-plan-mode.test.ts for the shared assertion
+ * contract. Exercises the same contract against /plan-design-review.
+ *
+ * Note: on no-UI-scope branches plan-design-review legitimately short-
+ * circuits to plan_ready without firing AskUserQuestion. Both 'asked' and
+ * 'plan_ready' are valid pass outcomes.
+ */
+
+import { describe, test, expect } from 'bun:test';
+import {
+  runPlanSkillObservation,
+  assertReportAtBottomIfPlanWritten,
+} from './helpers/claude-pty-runner';
+
+const shouldRun = !!process.env.EVALS && process.env.EVALS_TIER === 'gate';
+const describeE2E = shouldRun ? describe : describe.skip;
+
+describeE2E('plan-design-review plan-mode smoke (gate)', () => {
+  test('reaches a terminal outcome (asked or plan_ready) without silent writes', async () => {
+    const obs = await runPlanSkillObservation({
+      skillName: 'plan-design-review',
+      inPlanMode: true,
+      timeoutMs: 300_000,
+    });
+
+    if (obs.outcome === 'silent_write' || obs.outcome === 'exited' || obs.outcome === 'timeout') {
+      throw new Error(
+        `plan-design-review plan-mode smoke FAILED: outcome=${obs.outcome}\n` +
+          `summary: ${obs.summary}\n` +
+          `elapsed: ${obs.elapsedMs}ms\n` +
+          `--- evidence (last 2KB visible) ---\n${obs.evidence}`,
+      );
+    }
+    expect(['asked', 'plan_ready']).toContain(obs.outcome);
+    assertReportAtBottomIfPlanWritten(obs);
+  }, 360_000);
+});