feat: intent-based sign-in replaces account-type chooser
New sign-in flow:
- Default sign-in (header button, review-page CTA) → user account, no
chooser shown; user lands on /account/reviews dashboard.
- "Submit your project" CTA → carries intent=project through OAuth;
freshly-signed-in DID is auto-classified as a project and lands on
/explore/manage.
User → project upgrade (for accounts already signed in as users):
- A small "Submit your project" button appears at the top of the
/account/reviews dashboard.
- Clicking it opens a modal: "Is this account a project?"
- "Yes" → POSTs to /api/account/type, converts to project, redirects
to /explore/manage.
- A link lets users sign in with a different (project) account via
/oauth/add-account?intent=project, so the next sign-in is also
auto-classified as a project.
Removed:
- /account/type chooser page (replaced with a smart redirect for legacy
bookmarks/in-flight sessions; untyped DIDs default to user).
- requiresAccountTypeChoice helper (no longer needed).
Made-with: Cursor