chore: postpone annotations and add validation refinements

[Borda]

This pull request ports the useful Python typing and validation refinements from #2260 while keeping the branch focused.

Summary:

• Adds postponed annotation evaluation to the touched test modules.
• Modernizes the _yolo_dataset_factory classes annotation to list[str] | None.
• Adds targeted runtime validation for metric inputs so missing class_id or prediction confidence raises clear ValueErrors instead of lower-level NumPy/type errors.
• Adds COCO mask handling for malformed RLE segmentation dictionaries missing counts, preserving mask alignment with an empty mask and warning.
• Adds draw_image validation for undecodable files and unsupported image channel shapes.

Compatibility note:

• Metric classes now fail fast on missing required detection fields instead of silently skipping some prediction-only invalid inputs. This is intentional because those fields are required to compute meaningful detection metrics.

[codecov]

Codecov Report

❌ Patch coverage is 95.55556% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 82%. Comparing base (f34a940) to head (79abaf5).

Additional details and impacted files

@@           Coverage Diff           @@
##           develop   #2357   +/-   ##
=======================================
  Coverage       82%     82%           
=======================================
  Files           68      68           
  Lines         9523    9560   +37     
=======================================
+ Hits          7823    7881   +58     
+ Misses        1700    1679   -21     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Copilot]

Pull request overview

This PR modernizes the test suite by enabling postponed evaluation of type annotations (from __future__ import annotations) across test modules, aligning test typing behavior with newer Python typing patterns while keeping runtime behavior unchanged in tests.

Changes:

• Added from __future__ import annotations at the top of the test modules touched to postpone annotation evaluation.
• Updated _yolo_dataset_factory’s classes parameter annotation in tests/metrics/conftest.py from Optional[list[str]] to list[str] | None.

Reviewed changes

Copilot reviewed 27 out of 27 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/utils/test_video.py	Adds postponed-annotations future import.
tests/utils/test_iterables.py	Adds postponed-annotations future import.
tests/utils/test_internal.py	Adds postponed-annotations future import.
tests/utils/test_image.py	Adds postponed-annotations future import.
tests/utils/test_conversion.py	Adds postponed-annotations future import.
tests/utils/conftest.py	Adds postponed-annotations future import.
tests/tracker/test_byte_tracker.py	Adds postponed-annotations future import.
tests/metrics/test_recall.py	Adds postponed-annotations future import.
tests/metrics/test_precision.py	Adds postponed-annotations future import.
tests/metrics/test_oriented_bounding_box_metrics.py	Adds postponed-annotations future import.
tests/metrics/test_mean_average_recall.py	Adds postponed-annotations future import.
tests/metrics/test_mean_average_precision.py	Adds postponed-annotations future import.
tests/metrics/test_f1_score.py	Adds postponed-annotations future import.
tests/metrics/conftest.py	Adds postponed-annotations future import and modernizes one Optional[...] annotation to `
tests/key_points/test_skeletons.py	Adds postponed-annotations future import.
tests/key_points/test_core.py	Adds postponed-annotations future import.
tests/key_points/test_annotators.py	Adds postponed-annotations future import.
tests/geometry/test_utils.py	Adds postponed-annotations future import.
tests/geometry/test_core.py	Adds postponed-annotations future import.
tests/detection/utils/test_vlms.py	Adds postponed-annotations future import.
tests/detection/test_polygonzone.py	Adds postponed-annotations future import.
tests/detection/test_polygon_zone_annotator.py	Adds postponed-annotations future import.
tests/conftest.py	Adds postponed-annotations future import.
tests/assets/test_list.py	Adds postponed-annotations future import.
tests/assets/test_downloader.py	Adds postponed-annotations future import.
tests/annotators/test_docs.py	Adds postponed-annotations future import after module docstring.
tests/annotators/test_core.py	Adds postponed-annotations future import after module docstring.

[Copilot]

Pull request overview

Copilot reviewed 35 out of 35 changed files in this pull request and generated 2 comments.