Previous behavior: login-based accounts (Doodstream/VOE/Vidmoly) reported
'Login hinterlegt — Bereit' as long as username/password were non-empty.
Entering nonsense (asdas@web.de / anything) passed. Now:
- Vidmoly: POST /api/auth/login with JSON and verify /api/upload/config
is reachable afterwards — 401/403 or non-OK message → BadCredentials.
- Doodstream: login_ajax POST, success when either Dashboard HTML comes
back or json.status == 'success'; OTP-required is surfaced as
'Login gültig (OTP erforderlich)'.
- VOE: Laravel CSRF scrape + POST /login, then verify /file-upload
renders a fresh CSRF (only present when logged in).
- Clouddrop: 401/403 now mapped to BadCredentials instead of generic.
- Byse: parse JSON status field (server returns HTTP 200 + status:403
on bad keys) and map accordingly.
Bogus credentials now correctly show a red 'Fehler' state.