AADSTS700016 came from the register flow sending the configured
Oidc:ClientId (still a placeholder) as the auth client. The desktop
reference app never needs config: it bootstraps with the first-party
"Microsoft Graph Command Line Tools" public client (14d82eec-...) via
MSAL interactive, which exists in every tenant.
Replicate that for the web app. A server can't do MSAL loopback and the
bootstrap client's redirect URIs don't include /connect/callback, so use
the OAuth 2.0 device authorization grant instead — the web-equivalent of
the desktop interactive flow:
- Add EntraDeviceCodeFlow: POST /devicecode then poll /token with the
bootstrap client. No backing app, no client id/secret, no redirect URI.
- Profiles "Register in Entra" now shows the verification URL + user code
and polls until the admin signs in, then calls AppRegistrationService
to create the per-client app and adopts its appId.
- Remove the dead /connect/register-initiate endpoint and the
IsRegistration branch from the callback (connect flow only now).
The client-tenant register/connect flows are now fully secretless. The
Oidc:* config is used only by the toolbox's own sign-in (unchanged).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
