test: reduce default runner noise and contention

packages/core/package.json

@@ -22,7 +22,7 @@
   "scripts": {
     "build": "tsc",
     "typecheck": "tsc --noEmit",
-    "test": "vitest run"
+    "test": "vitest run --silent=passed-only --reporter=dot"
   },
   "devDependencies": {
     "@types/node": "^25.5.0",

packages/core/vitest.config.ts

@@ -1,7 +1,7 @@
 import { defineConfig } from "vitest/config";
 import { availableParallelism } from "node:os";
 
-const defaultMaxWorkers = Math.max(1, Math.min(4, Math.ceil(availableParallelism() / 8)));
+const defaultMaxWorkers = Math.max(1, Math.min(2, Math.ceil(availableParallelism() / 8)));
 const maxWorkers = Number.parseInt(process.env.VITEST_MAX_WORKERS ?? String(defaultMaxWorkers), 10);
 
 export default defineConfig({