🔨 Changes
- Fixed type checking errors in marketplace.py
- Added proper error handling for NostrClient
- Improved string type conversions
- Fixed JSON input handling in publish_stall_by_name
- Made error response formats consistent
🧰 Development
- Added black for code formatting
- Added isort for import sorting
- Added mypy for type checking
- Updated CONTRIBUTING.md with development setup
- Added GitHub Actions for test and build
🔍 Quality
- Added mypy configuration
- Fixed variable redefinitions
- Added proper type hints
- Improved error handling
- Added automated code quality checks