Add Stock Market Agent-Based Model Example

Hi Mesa team,

I would like to contribute a stock market agent-based model as a new example for mesa-examples.

The model includes:

• Trader agents
• Price formation based on supply and demand
• Agent interactions and sentiment effects

I am currently building and testing it and would like to know if this would be a useful addition.

Looking forward to your feedback.

Thank you.

The issue proposes a new stock-market agent-based model for mesa-examples, including trader agents, supply-and-demand price formation, and sentiment effects. No files, tests, entry points, or acceptance criteria are named; clarify the intended model scope and example location before implementation. Done is not defined beyond deciding whether this is a useful addition.

Written by the indexing model from the issue text.