Add Nostr relay + seed data to Docker deployment

- Add nostr-rs-relay service to docker-compose for persistent
  comments, reactions, and profiles on the dev server
- Add one-shot seeder container that auto-populates the relay
  with test personas, reactions, and comments on first deploy
- Proxy WebSocket connections through nginx at /relay so the
  frontend connects to the relay on the same host (no CORS)
- Make relay URL dynamic: reads from VITE_NOSTR_RELAYS in dev,
  auto-detects /relay proxy path in production Docker builds
- Make seed scripts configurable via RELAY_URL and ORIGIN env vars
- Add wait-for-relay script for reliable container orchestration
- Add "Resume last played" hero banner on My List tab

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -12,6 +12,10 @@ RUN npm ci
 # Copy source code
 COPY . .
 
+# Clear VITE_NOSTR_RELAYS so the app auto-detects the relay
+# via the /relay nginx proxy at runtime (instead of hardcoding localhost)
+ENV VITE_NOSTR_RELAYS=""
+
 # Build the application
 RUN npm run build