fix: Enforce string type for Agent 'name' parameter

[Hafiz-Muhammad-Umar12]

This Pull Request addresses an inconsistency between the documentation and the runtime behavior of the Agent class.

The issue identified:

• The documentation for the Agent class states that the name property is a required string.
• However, the code did not strictly enforce this, allowing non-string values (e.g., integers) to be passed without raising an error. This could lead to unexpected behavior in downstream components and creates confusion for developers.

The solution:

• A runtime check has been added to the __post_init__ method of the AgentBase class.
• This check now strictly enforces that the name parameter must be a string, raising a TypeError if an invalid type is provided.

Why this is important:

• Consistency: The code now accurately reflects what is stated in the documentation, making the SDK more reliable.
• Clarity: Developers will receive an immediate and clear error message if they attempt to use an incorrect type, significantly

[seratch]

Thanks for sending this. We're going to resolve this issue by #998