Base login now requests only openid/email/profile (non-sensitive), so a new user
gets a clean Google consent with no "unverified app" warning and no 7-day refresh
token expiry. YouTube read (youtube.readonly) and write (youtube) are granted later
by the onboarding wizard via a parameterized /auth/upgrade?access=read|write.
Security fixes folded in from the baseline audit:
- config: refuse to boot in production (https OAUTH_REDIRECT_URL) with the
placeholder/short SECRET_KEY or a missing TOKEN_ENCRYPTION_KEY, closing a
session-forgery / admin-impersonation hole.
- main: mark the session cookie Secure when served over HTTPS.
- me: expose can_read; sync/subscriptions returns a friendly 403 (not a 500)
until YouTube read access is granted.
4765db89de