* refactor docstrings in `scr/supervision/detection`
* Enhance docstrings across multiple modules: clarify attributes/args, improve formatting, and update logic for handling sentinel values in metrics calculation.
* Ensure consistent handling of `class_id` as integer across YOLO and Pascal VOC formats, fix NoneType handling in line zone logic, and add test coverage for multiclass annotator with None `class_id`.
* Enforce `class_id` as integer in YOLO export, update line zone class count docstrings, and add test for non-integer `class_id`.
* Apply suggestions from code review
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Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* refactor: reorganize project structure and update module imports
* configure setuptools to use 'src' layout and adjust package discovery
* refactor: move tests to `tests` directory and update imports accordingly
* update lint and mypy configurations to align with `src` and `tests` structure
* update test imports to use corrected `tests.helpers` module path
* fix(pre_commit): 🎨 auto format pre-commit hooks
