The one click that opens Google's consent screen already existed. What it needs
behind it is a registered client, and no app can conjure one: Google issues no
Gmail access to an unregistered client, and `gmail.readonly` is a restricted
scope, so an id shipped inside a public image would be both extractable from it
and unusable without Google's security review of every deployment using it.
The registration is a one-off. Having to edit a Rune's manifest and recreate the
container to paste the result was not.
`VERDANDE_GMAIL_CLIENT_ID` and `_SECRET` still win when set. A value in the
environment is a deliberate deployment decision, applied again on every recreate,
and a form that could quietly override it would make the manifest a lie — so the
page says where the value came from, and PUT answers 409.
The redirect URI is spelled out on the page rather than left to be reconstructed.
It is derived from VERDANDE_BASE_URL, it has to match Google's copy exactly, and
the error Google returns when it does not names neither value.
Its own table rather than `user_settings`: an OAuth client is the instance's, not
one person's — and `user_settings` has `user_id` as its whole primary key, so a
second scope there would silently overwrite the AI provider's key.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
