## Summary
Fixes the blank `/authorize` page reported when a user reopens the OAuth
consent screen on `app.twenty.com` after a prior multi-workspace SSO
sign-in.
### Reproduction
1. ChatGPT (or any MCP client) opens
`https://app.twenty.com/authorize?client_id=…` while signed out.
2. User picks "Continue with Google", lands in workspace selection,
picks a workspace, authorizes the app. Works.
3. Some time later, ChatGPT re-opens
`https://app.twenty.com/authorize?client_id=…`.
4. **Observed:** fully blank page, no console errors. Deleting the
`tokenPair` cookie unblocks it.
### Root cause
The multi-workspace social-SSO branch
([auth.service.ts:988-1011](https://github.com/twentyhq/twenty/blob/main/packages/twenty-server/src/engine/core-modules/auth/services/auth.service.ts#L988-L1011))
lands the user on `app.twenty.com/welcome?tokenPair=…` with a
workspace-agnostic token. `SignInUpGlobalScopeFormEffect` writes that
into the host-scoped `tokenPair` cookie on `app.twenty.com`, and nothing
clears it after the user proceeds to a workspace subdomain. On the next
visit to `app.twenty.com/authorize?…`, `MinimalMetadataGater` sees
`hasAccessTokenPair === true` and renders `<UserOrMetadataLoader />`
instead of `<Authorize />`. The loader never goes away because:
- `IsMinimalMetadataReadyEffect` waits for `metadataStore.status ===
'up-to-date'`.
- `MinimalMetadataLoadEffect` only loads metadata when
`hasAccessTokenPair && isActiveWorkspace`, and the default domain has no
workspace context.
Skeleton loader stays forever → user perceives "blank page".
Some users get rescued by `WorkspaceProviderEffect` auto-redirecting
them to their last-authenticated workspace subdomain, but that cookie is
set with `domain: .twenty.com` and silently fails to persist for users
on custom domains — so the bug is most visible there.
### Fix
`/authorize` only issues `findApplicationRegistrationByClientId`, which
is a `PublicEndpointGuard` query. It doesn't need workspace metadata.
Add it to the gater's excluded-paths list alongside the existing
pre-auth pages (`SignInUp`, `Verify`, `Invite`, …) so the page renders
immediately regardless of token state.
This is a one-line, minimum-blast-radius fix. Two related cleanups are
separate concerns and not addressed here:
- Clearing the workspace-agnostic `tokenPair` cookie on `app.twenty.com`
after workspace selection.
- Fixing `lastAuthenticatedWorkspaceDomain` propagation for
custom-domain users.
## Test plan
- [x] `npx oxlint` + `prettier --check` on the touched file — clean.
- [x] `npx nx typecheck twenty-front` — clean.
- [ ] Manual: with a stale `tokenPair` cookie set on `app.twenty.com`,
open `https://app.twenty.com/authorize?client_id=<valid>&…` — consent
screen renders, no blank.
- [ ] Manual: signed-out → open the same URL — still redirects to
`/welcome` and back through the flow.
- [ ] Manual: signed-in on a workspace subdomain → open
`https://app.twenty.com/authorize?…` — `WorkspaceProviderEffect`
auto-redirect still kicks in (unchanged behavior).
