Critical:
- build script now copies launcher menu + china guide (was missing!)
- Windows PATH: handle fresh accounts + warn on 1024 char limit
- Windows .bat: remove old .env keys before adding new (no duplicates)
Important:
- Menu error message: fix range 0-14 → 0-16
- API key input: use read -s to hide plaintext
- macOS install: default to .zshrc (not .bash_profile)
- Website table: fix column mismatch (td → span inside td)
