Summary of Changes

Hello @jorellis, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request primarily focuses on enhancing the type safety and maintainability of the Python codebase by resolving mypy type errors, especially those concerning eth-account types. It includes significant refactoring of type hints, updates to dependency management, and adjustments to core payment processing and agent interaction logic to align with stricter type checking and Pydantic v2 best practices.

Highlights

• Mypy Type Error Resolution: Addressed various mypy type errors, particularly those related to the distinction between eth-account's Account and LocalAccount types, ensuring type correctness across the codebase.
• Refined Type Usage: Updated type hints in x402_a2a/core/wallet.py and x402_a2a/executors/client.py to use LocalAccount where appropriate and introduced typing.cast to Account when interacting with external libraries that expect the more generic type.
• Dependency and Configuration Updates: Modified uv.lock files to include new greenlet wheels and added mypy>=1.18.0 to linting dependencies. pytest and pytest-asyncio were moved to the dev dependency group in pyproject.toml.
• A2A Type Alignment and Pydantic V2 Refinements: Updated AgentCard creation to use direct keyword arguments and aligned message creation with a2a.types by using Part(root=TextPart(...)) and Role enum, and adjusted field names like messageId to message_id.
• Payment Processing Logic Enhancements: Improved payment processing in wallet.py and client.py by using Web3.to_checksum_address for asset contracts, updating authorization data keys, and refining the _auto_pay mechanism to directly enqueue payment submission messages.
• Robust Error Handling and Context Management: Enhanced error handling and context management in server.py by adding explicit checks for None task/context IDs, refining payment status extraction, and improving metadata handling for task status messages.