fix: handle direct model answers in ReACT loop

[markstur]

Misc PR

Type of PR

• Bug Fix
• New Feature
• Documentation
• Other

Description

• Link to Issue: Fixes fix: react loop is missing a check for result without tool calls #762

fix: handle direct model answers in ReACT loop

The ReACT framework now properly handles cases where the model provides
a direct answer without calling tools. Previously, these answers were
ignored and the loop would continue until exhausting the budget.

Added test coverage for both scenarios (no tools, unused tools).

Testing

• Tests added to the respective file if code was changed
• New code has 100% coverage if code as added
• Ensure existing tests and github automation passes (a maintainer will kick off the github automation when the rest of the PR is populated)

[github-actions]

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[markstur]

Note to reviewers: I do have concerns about my limited test environment and side effects. I'm seeing this as a good fix for when react_using_mellea with DuckDuckGo starts to find nothing. I suspect it could be impacted by DDGS rate limiting but not sure why it looks like this. Bottom line though is that there is a case where we have an answer in step value (is_complete) but we miss our is_final handling.

I wonder if there is any reason to only do this check after running out of iterations (last ditch handling), but it seem seems more right to me to just use the value when this elif case happens.