Add scenarios from NegotiationArena

[Keyu-He]

No description provided.

[XuhuiZhou]

Please follow every rule when making a pull request. (i.e., check the pull request template and follow the instructions in contributing: https://docs.sotopia.world/contribution/contribution)

Have you run any of those scripts and checked the simulations are actually running?

[Keyu-He]

📑 Description
Add scenario examples from NegotiationArena

✅ Checks

• My pull request adheres to the code style of this project
• My code requires changes to the documentation
• I have updated the documentation as required
• All the tests have passed
• [N/A] Branch name follows type/descript (e.g. feature/add-llm-agents)
• Ready for code review

ℹ Additional Information
Yes I’ve run all of the scripts and confirmed that the simulations execute correctly. These commits only address the mypy type errors—no API changes or new features—so documentation updates aren’t needed.