chore: migrate to context API

[open-swe]

Fixes #12

Context API Migration

This pull request completes a comprehensive migration to the new LangGraph Context API, following the memory-agent pattern. The changes include:

Key Updates

• Replaced Configuration class with new Context dataclass
• Updated all modules to use new Context API
• Migrated from config={'configurable': {...}} to context=Context(...) pattern
• Updated LangGraph dependency to langgraph>=0.6.0,<0.7.0

Changes Implemented

• Created new context.py with Context class
• Updated graph.py, tools.py, and utils.py to use new Context API
• Removed configuration.py
• Updated unit and integration tests
• Ensured code quality through formatting and linting checks

Migration Highlights

• Added environment variable support via __post_init__ method
• Maintained existing configuration logic
• Improved type hinting and runtime context handling

Testing

• All unit tests passing
• Integration tests verified (with external API credential caveat)
• Full linting and formatting checks completed

The migration provides improved type safety, better runtime context management, and aligns with the latest LangGraph best practices.