"Different account detected" screen is unreachable

[saqibmanan]

What: Signing in with a second Google identity whose email matches an account already linked to Google returns HTTP 409, and the user sees the generic error page. LoginIdpLinkConfirmOverride.tsx never renders in this flow.
Evidence: error="identityProviderAlreadyLinkedToCurrentUserMessage"
Fix: not fixed — confirm which Keycloak flow should reach the override page, or drop the screen.

[saqibmanan]

Repro: account already linked to Google identity A; sign in with Google identity B that has the same email → Existing account found → Continue with Google → email link.

Observed: HTTP 409 on /broker/after-first-broker-login, event IDENTITY_PROVIDER_LOGIN_ERROR, error=identityProviderAlreadyLinkedToCurrentUserMessage; UI shows "Google sign-in failed".
login-idp-link-confirm-override.ftl ("Different account detected") never rendered in any flow tried.