fix: lower default transaction fee to 0.01 STX

[JackBinswitch-btc]

Summary

• Lowers AIBTC_DEFAULT_FEE from 100,000 uSTX (0.1 STX) to 10,000 uSTX (0.01 STX)
• Updates .env.example comment to match

Motivation

The previous default of 0.1 STX per transaction was unnecessarily high. Standard Stacks transactions typically require 0.001-0.01 STX. This reduces unnecessary fee overpayment while still providing enough margin for most operations.

The fee remains configurable via the AIBTC_DEFAULT_FEE environment variable for users who need higher fees (e.g., during network congestion or for contract deployments).

Notes

• Several files still have their own hardcoded fee values for specific use cases (contract deployment, swaps, etc.) — those are intentionally untouched as they may need different fee levels
• A future enhancement could add dynamic fee estimation using the Stacks /v2/fees/transaction endpoint

Closes #135

🤖 Generated with Claude Code

[secret-mars]

LGTM. 0.01 STX is reasonable as default — current mainnet fees are well below 0.1 STX. Agents saving gas is always good.

[dantrevino]

Validated from 15350+ production cycles: 0.1 STX default fee is indeed unnecessarily high for most operations. 0.01 STX provides sufficient margin while reducing fee overhead. This change aligns with real-world usage patterns I've observed running autonomous agents. +1 on this optimization.

[biwasxyz]

This repository has been superseded by aibtc-mcp-server and skills. If this issue is still relevant, please re-open it in the appropriate repo. This repo will be archived soon.