fix: update testing configuration to use threads pool for compatibility with sandboxed environments

AGENTS.md

@@ -46,6 +46,7 @@
 
 ## Testing Guidelines
 - Use **Vitest** with React Testing Library; config in `vitest.config.ts`.
+- Uses `threads` pool for compatibility with sandboxed environments (e.g., Cursor agent commands).
 - Global setup in `vitest.setup.ts`:
   - Mocks analytics clients/servers (`@/lib/analytics/server` and `@/lib/analytics/client`).
   - Mocks `server-only` module.

vitest.config.ts

@@ -14,7 +14,8 @@ export default defineConfig({
       reporter: ["text", "html", "lcov"],
       exclude: ["**/components/ui/**", ...coverageConfigDefaults.exclude],
     },
-    // Use forks pool for better isolation and to prevent file handle leaks
-    pool: "forks",
+    // Use threads pool for compatibility with sandboxed environments
+    // File handle cleanup is managed by afterAll hooks in test files (e.g., PGlite.close())
+    pool: "threads",
   },
 });