fix(FN-2116): show paused agents and cap vitest workers

plugins/examples/fusion-plugin-settings-demo/vitest.config.ts

@@ -1,8 +1,12 @@
 import { defineConfig } from "vitest/config";
 
+const requestedMaxWorkers = Number.parseInt(process.env.VITEST_MAX_WORKERS ?? "1", 10);
+const maxWorkers = Math.max(1, Math.min(1, Number.isFinite(requestedMaxWorkers) ? requestedMaxWorkers : 1));
+
 export default defineConfig({
   test: {
     include: ["src/**/*.test.ts"],
     pool: "threads",
+    maxWorkers,
   },
 });