[Improve] Offer communications after source control for email setup

[roomote-roomote]

​Created by Roomote. Follow up by mentioning @roomote-roomote, in the web UI, or in Slack.

What changed

• Reorders email/password setup so inference and source control are configured before communications.
• Preserves the existing communications-first sequence when Slack or Microsoft Teams is selected during account authentication.
• Carries the email/password choice across the sign-in boundary once, while clearing stale choices before provider authentication.

Why this change was made

Email/password users should establish the core inference and repository connections before choosing where Roomote communicates, without changing the combined authentication and communications setup offered by Slack or Teams.

Impact

New email/password setup sessions now follow Welcome, Auth, Inference, Source Control, Comms, Automation Recommendations, Environment Creation, and Invoke. Existing Slack and Teams authentication flows retain their current ordering. Browser proof could not be captured because the seeded local account had already completed setup and no unconfigured account state was available through the normal product flow.

[roomote-community]

1 issue outstanding. See task

• Preserve the email setup ordering through source-control OAuth returns (apps/web/src/app/(onboarding)/setup/SetupSignedInFlow.tsx:86).

_{Reviewed 484d9d2}

[roomote-community]

Consuming this flag on the first signed-in mount means it is gone after any full-page setup redirect. Source-control setup deliberately redirects to OAuth and returns to /setup?step=source-control-connect; on that return the default communications-first sequence is selected, so the deep link is clamped to the still-pending communication chooser. Preserve the email-flow ordering for the signed-in setup session (or through the source-control redirect) so email users can complete source-control setup before communications.