Add optional SATS-402 wrapper example for Bitcoin-native paid Actor delivery

[Lumen-Founder]

Summary

Adds a small optional SATS-402 wrapper example/docs pointer for Bitcoin-native paid delivery of Apify Actor results.

This is unofficial and optional. It can be moved, edited, reduced, or closed by maintainers.

Apify already leads in agentic payments with x402/Skyfire. SATS-402 demonstrates a complementary Bitcoin-native paid-delivery path using Lightning preimage-locked response delivery.

Standalone proof repo:

https://github.com/Lumen-Founder/apify-sats402-wrapper

Related issue:

#756

Notes

• Does not bypass Apify auth.
• Does not bypass Apify billing.
• Does not bypass Apify API tokens.
• Does not bypass Apify usage limits or rate limits.
• Real upstream mode uses a normal APIFY_TOKEN.
• Fixture mode supports local verification without an Apify token.
• The proof path uses local real-LND regtest for hold-invoice/payment/preimage settlement.

Demo command:

npm run apify:demo -- --actor apify/rag-web-browser --query "bitcoin lightning agent payments"