test: implement integration tests (L2-4), Pinia store unit tests (L5), and Playwright E2E tests (L6)

Forecast, dashboard, pronunciation, nginx fixes (exclude large ML weights)

add test ielts band for new user

covertation + security

update reading-listening + phát âm vob

huy hieu + notification

feat: admin

mupdate vocabulary

update reading + listening

first commit