Enable Onchain Bitcoin Payments

[gudnuf]

🎯 Goal

Enable users to reliably send and receive onchain Bitcoin through Cashu mints with good UX.

📊 Success Metrics

• NUT-26 specification approved and merged
• At least 1 production mint offering onchain
• At least 2 wallets with onchain UI implemented
• 95% success rate for onchain transactions

🚧 Current Reality

• Specification: NUT-26 in PR, under review
• Production mints: 0 with onchain
• Wallet support: 0 with UI
• Backend: Only FakeWallet exists

🔴 Critical Blockers

1. No production Bitcoin backend
2. Confirmation UX not designed
3. Fee economics unknown

📈 Readiness: 15/100

🔗 Related Work

• NUT-26: onchain bitcoin payment method cashubtc/nuts#283
• CDK: onchain cashubtc/cdk#995
• cashu-ts: implement onchain (NUT-26) cashubtc/cashu-ts#349