Idempotent seeder inserts public, unowned demo scenarios from
backend/app/seed_data/*.json if a public scenario with the same title
is missing, so a fresh Neon database (and any clone) gets demo content
guests can play immediately. Ships two scenarios: the Sunken Crypt of
Vharos (all four script hooks) and Signal from the Derelict (sci-fi,
context-engine focused).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TEpWMjnfPqzZ13nPMoGhs5
