Database — From Placeholder to Real Data

Turn the static, placeholder-driven app into a dynamic one backed by Supabase (PostgreSQL). The types bootstrap seeded become tables; the wireframe's realistic fake data becomes seed rows — so the app looks identical after this skill runs, except now the data is real and editable.

Scope check (Step 0 rule)

Read codehance.md first. This skill owns component 7 (Database) and completes 6 (Backend API):