[P0-2] Supabase Schema

[realproject7]

Context

Set up the database schema from the proposal. Three tables: storylines, plots, donations. The schema includes deduplication constraints (UNIQUE(tx_hash, log_index)), foreign keys, and an indexer-set writer_type column. Also add a hidden boolean column (default false) to storylines and plots for MVP content moderation (§8 Risks table).

Sub-tickets

• P0-2a: Create SQL migration file(s) with all three tables exactly as specified in §4.1, plus the hidden column on storylines and plots.
• P0-2b: Create Supabase client helper (lib/supabase.ts) — server-side client using service role key, and a browser-side client using anon key. Follow the pattern used in other project repos (dropcast, reviewme-fun).

Proposal Reference

§4.1 (Supabase Schema)