fix: isolate artifact rebuild from release suites

release-gate/runner.test.mjs

@@ -1,7 +1,7 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
 
-import { parseRunnerArgs, runWithConcurrency } from './runner.mjs';
+import { parseRunnerArgs, runSuitesWithConcurrency, runWithConcurrency } from './runner.mjs';
 
 test('runner accepts a bounded suite concurrency and rejects unsafe values', () => {
   assert.equal(
@@ -31,3 +31,24 @@ test('runWithConcurrency preserves result order and never exceeds its worker bud
   assert.deepEqual(results, ['result-0', 'result-1', 'result-2', 'result-3']);
   assert.equal(peak, 2);
 });
+
+test('exclusive suites finish before parallel suites start', async () => {
+  const events = [];
+  const results = await runSuitesWithConcurrency(
+    [
+      { id: 'mutating', exclusive: true },
+      { id: 'parallel-a' },
+      { id: 'parallel-b' },
+    ],
+    2,
+    async (suite) => {
+      events.push(`start:${suite.id}`);
+      await new Promise((resolve) => setTimeout(resolve, 5));
+      events.push(`end:${suite.id}`);
+      return suite.id;
+    },
+  );
+  assert.deepEqual(results, ['mutating', 'parallel-a', 'parallel-b']);
+  assert.ok(events.indexOf('end:mutating') < events.indexOf('start:parallel-a'));
+  assert.ok(events.indexOf('end:mutating') < events.indexOf('start:parallel-b'));
+});