fix: log toolbox tool results with the correct metadata

[atharvasingh7007]

Summary
fix toolbox-backed tool-result logging so each result uses its own tool metadata
update the mixed-toolbox logging regression to assert Memory results stay attributed to Memory

Root cause
_BaseResponse.log_to_db() reused the ool loop variable from the earlier or tool in self.prompt.tools loop when inserting ool_instances rows for self.prompt.tool_results. In Python that leaked the last tool from the previous loop, so mixed toolbox runs logged every result against the last toolbox.

Testing
C:\Users\Atharva\Documents\CODEX\llm.venv\Scripts\python.exe -m pytest tests/test_plugins.py
C:\Users\Atharva\Documents\CODEX\llm.venv\Scripts\python.exe -m ruff check .
C:\Users\Atharva\Documents\CODEX\llm.venv\Scripts\python.exe -m mypy llm

Closes #1398