Add 15 new tests in two classes:
- TestRmFalsePositiveFix (8 tests): verify filenames starting with 'r'
(readme.txt, requirements.txt, report.csv, etc.) are NOT falsely
flagged as 'recursive delete'
- TestRmRecursiveFlagVariants (7 tests): verify all recursive delete
flag styles (-r, -rf, -rfv, -fr, -irf, --recursive, sudo rm -rf)
are still correctly caught
All 29 tests pass (14 existing + 15 new).
- Renamed test method for clarity and added comprehensive tests for `SessionSource` including handling of numeric `chat_id`, missing optional fields, and invalid platforms.
- Introduced tests for session source descriptions based on chat types and names, ensuring accurate representation in prompts.
- Improved file tools tests by validating schema structures, ensuring no duplicate model IDs, and enhancing error handling in file operations.
