Remove broken onboarding steps and fetch profile data from Bluesky
Remove suggested-accounts, suggested-starterpacks, and find-contacts
onboarding steps since their backing API endpoints return empty or
error on our appview. Onboarding flow is now profile -> interests ->
finished.
Remove the backfill-in-progress badge from profile headers. Instead,
fetch follower/following/post counts and known followers from Bluesky's
appview via atproto-proxy, falling back to local data only when a user
is suspended on Bluesky but not on our side.