fix: correct WebSearchState id type

[Benny45123]

PR Title

Fix WebSearchState.id type mismatch

PR Description

Fixes #221

Summary

Updates WebSearchState.id from str to int in
backend/src/agent/state.py to match how the value is used throughout the graph.

Details

• continue_to_web_research() passes integer IDs through LangGraph Send.
• evaluate_research() also generates integer IDs for follow-up searches.
• resolve_urls() explicitly accepts id: int.
• The existing str annotation caused the state schema to differ from the actual runtime values.

This change aligns the type annotation with the existing implementation without changing runtime behavior.

Files changed: 1
Behavioral changes: None.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[gemini-code-assist]

Code Review

This pull request updates the type of the id field in the WebSearchState class from str to int in backend/src/agent/state.py. There are no review comments, and I have no feedback to provide.