[Adnan9-63]

Fixes Issue

Closes #1593

Changes proposed

• Updated get_input_file_type() in slips/main.py to rigorously validate Zeek directories. It now checks every item in the folder and cleanly throws an error if it encounters subdirectories, empty directories, or invalid files (not ending in .log or .log.labeled), preventing IsADirectoryError crashes.
• Added comprehensive unit tests in tests/unit/slips/test_main.py (test_get_input_file_type_zeek_folder) covering valid, empty, subdirectory, and invalid file scenarios.

Steps I followed to test the changes proposed in this PR:

• Ran python3 -m pytest tests/unit/slips/test_main.py directly, passing all assertions for the validation logic.
• Ran the entire canonical unit test suite, resulting in 100% pass rate.
• Verified the directory iteration logic handles ignored log files gracefully.

Check List

• My code follows the code style of this project.
• My change requires changes to the documentation.
• I have updated the documentation accordingly.
• All new and existing tests passed.
• This PR does not contain plagiarized content.
• The title of my pull request is a short description of the requested changes.
• My PR is based on develop branch. (mandatory)

Note to reviewers

Fixes #1593. ZeekDirInput previously threw an IsADirectoryError if os.listdir()[0] was a subdirectory. This PR strictly enforces that the -f directory contains exclusively valid zeek log files, cleanly printing an error otherwise.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[eldraco]

Thanks @Adnan9-63 , let us check it