Project selector no longer races against the user record after sign in

A subtle race condition lived in the project selector. Right after signing in, the selector occasionally rendered an empty list — not because you had no projects, but because the dropdown loaded before the user record was fully hydrated. A page refresh fixed it, but page refreshes are not a fix.

The project selector now waits for the user record to be available before populating its options. The correct default project is selected on every sign-in, and you do not have to refresh to see your own work.