fix(detection): keep from_inference aligned on partial masks

[kounelisagis]

Bug

process_roboflow_result appends a mask only for predictions that carry one (RLE or polygon), but appends xyxy, confidence and class_id for every prediction. A result that mixes masked and box-only predictions therefore ends up with a mask array shorter than the boxes, and Detections.from_inference raises:

ValueError: mask must be a 3D np.ndarray with shape (2, H, W), but got shape (1, H, W)

This shows up with segmentation results where one polygon is empty/degenerate and falls back to a box, so part of the batch has masks and part does not.

This is the same shape of issue as #2353 (partial tracker_id), in the same function; the mask path was the remaining case.

Fix

Append None for box-only predictions to keep the list aligned, and build the mask array only when every prediction has a mask, otherwise drop masks (with a warning) to preserve alignment with xyxy. Fully-masked and mask-free results are unchanged. Missing entries are detected by identity (mask is None) since None in masks would compare numpy arrays element-wise and raise.

Tests

Added an end-to-end from_inference test for a mixed masked/box-only batch, and updated the existing process_roboflow_result case that previously documented the misalignment as a known limitation.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82%. Comparing base (09b2199) to head (d637e91).

Additional details and impacted files

@@           Coverage Diff           @@
##           develop   #2362   +/-   ##
=======================================
  Coverage       82%     82%           
=======================================
  Files           68      68           
  Lines         9560    9564    +4     
=======================================
+ Hits          7881    7885    +4     
  Misses        1679    1679           

🚀 New features to boost your workflow:

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