Portabase creates the default admin from AUTH_DEFAULT_PASSWORD and checks it
with assertValidPassword (src/utils/password.ts): at least 8 characters, an
uppercase letter, a lowercase letter, a number and a special character. The
generated password is alphanumeric only, so the first start fails with
"Password must contain at least 1 special character".
Generate until each class is present rather than appending fixed characters,
and leave #, $, quotes and backticks out of the charset, because the value is
written unquoted into .env.
Fixes#17370
Co-authored-by: Claude Opus 5 <claude-opus-5@anthropic.com>