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/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "..",
+    "noEmit": true,
+    "types": ["jest", "node"]
+  },
+  "exclude": []
+}