test: add jest test suite with controller specs and mocks

- add jest, ts-jest, supertest, and related dev dependencies
- add test scripts (test, test:debug, test:watch) to package.json
- add jest.config.js with ts-jest transform and module name mappers
- add controller specs for auth, browser, environment, mcp, scenario, session
- add mocks for jsdom, playwright, and readability
- add test/tsconfig.json and exclude test dir from main tsconfig

test/__mocks__/jsdom.ts

@@ -0,0 +1,6 @@
+export class JSDOM {
+  constructor(public html: string, public options?: any) {}
+  get window() {
+    return { document: {} };
+  }
+}