AI inference (especially DeepSeek) often exceeds the default 120s HTTP
timeout, causing the client to disconnect while the server completes
successfully — resulting in repeated payments on each retry.
Changes:
- Set X402Timeout = 5min for all x402 providers (Claw402, BlockRunBase, BlockRunSol)
- Handle 402 during payment retry by re-extracting Payment-Required
header and re-signing instead of failing immediately
- Increase payment retry attempts from 3 to 5 for unstable gateways