chore: Migrate to vitest (#12272)

* wip

* Remove obsolete snapshots

* simplify

* chore(test): Convert mocks to TypeScript and tighten fetch mock types

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* Remove unneccessary patches

* Migrate to msw instead of custom fetch mock

* Address PR review comments

- Split chained vi.useFakeTimers().setSystemTime() into separate calls.
- Switch test setup to dynamic imports so EventEmitter.defaultMaxListeners
  assignment runs before module init (static imports were hoisted above it).
- Drop redundant NODE_ENV guard in monkeyPatchSequelizeErrorsForJest; its
  sole caller already gates on env.isTest.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

plugins/search-postgres/server/PostgresSearchProvider.test.ts

@@ -21,7 +21,7 @@ import PostgresSearchProvider from "./PostgresSearchProvider";
 const provider = SearchProviderManager.getProvider();
 
 beforeEach(async () => {
-  jest.resetAllMocks();
+  vi.resetAllMocks();
   await buildDocument();
 });