feat: integrate FlareSolverr for Cloudflare bypass on clone sources

- Add FLARESOLVERR_URL env var to .env.example
- Update fetchSourceFurnidata to fall back to FlareSolverr on CF challenges (403/HTML)
- Add docker-compose.yml with FlareSolverr service
- Add scripts/health-check.sh for FlareSolverr readiness check
- Add health:check script to package.json
- Document FlareSolverr setup in README

.env.example

@@ -71,3 +71,6 @@ PAYPAL_API=https://api-m.sandbox.paypal.com
 
 # --- LOGGING ---
 LOG_LEVEL=error
+
+# --- FLARESOLVERR (Cloudflare bypass for clone sources) ---
+FLARESOLVERR_URL=http://localhost:8191