Adds two tests for _handle_retry_command: verifies /retry returns the
agent response (not None), and verifies graceful handling when no
previous message exists.
Cherry-picked from PR #731 by teyrebaz33. Regression coverage for
the fix merged in PR #441.
Co-authored-by: teyrebaz33 <teyrebaz33@users.noreply.github.com>
- Add _repair_tool_call(): tries lowercase, normalize, then fuzzy match (difflib 0.7)
- Replace 3-retry-then-abort with graceful error: model receives helpful message and self-corrects
- Conversation stays alive instead of dying on hallucinated tool names
Closes#520
teyrebaz33