This PR updates the LangChain Arcade integration to v1.0.0, making the
following key changes:
• Bumped the package version in pyproject.toml from 0.2.0 to 1.0.0.
• Changed the default parameter in ArcadeToolManager from
langgraph=False to langgraph=True.
• Updated dependencies to require langgraph≥0.2.67,<0.3.0 and simplified
extras.
• Adjusted example scripts to remove explicit authorization_url
references in favor of a unified URL field.
• Updated docs and environment references to align with new usage
patterns and emphasize environment variables.
These changes unify and streamline the LangGraph-based tooling while
ensuring compatibility with the latest 1.0.0 release.
