Onboarding Flow Summary

Step 1 (0%)   → POST /onboarding/account/create
                POST /onboarding/account/google
                GET  /onboarding/account/check-handle
                GET  /onboarding/account/check-email

Step 2 (20%)  → GET  /onboarding/categories
                POST /onboarding/category

Step 3 (40%)  → GET  /onboarding/social/platforms
                POST /onboarding/social/connect
                POST /onboarding/social/callback
                POST /onboarding/social/skip

Step 4 (60%)  → GET  /onboarding/import/options
                GET  /onboarding/import/playlists
                GET  /onboarding/import/videos
                POST /onboarding/import/playlists
                POST /onboarding/import/videos
                POST /onboarding/import/links
                POST /onboarding/import/upload
                GET  /onboarding/import/status  (poll)

Step 5 (80%)  → GET  /onboarding/monetization/options
                GET  /onboarding/monetization/estimate
                POST /onboarding/monetization/setup

Step 6 (100%) → GET  /onboarding/review
                POST /onboarding/payout/connect
                POST /onboarding/launch

State Mgmt    → GET  /onboarding/progress
                PATCH /onboarding/progress