Fix #1274: Rename and fix PadIfNeeded to only pad (no crop)

[abhayrajjais01]

Summary

This PR fixes Issue #1274 where PadIfNeeded was incorrectly cropping images larger than the target size because it was aliased directly to Kornia.PadTo.

Changes

• New PadIfNeeded Class: Implemented a custom PadIfNeeded augmentation (inheriting from GeometricAugmentationBase2D) that:
  • Checks if the input image dimensions are smaller than the target size.
  • Pads only if needed.
  • Returns the identity (unchanged image) if the image is already larger than the target size.
• Added PadTo: Added a new key "PadTo" to _SUPPORTED_TRANSFORMS that maps to the original Kornia.PadTo behavior. This preserves backward compatibility for users who relied on the cropping behavior.
• Tests: Added a new regression test test_pad_if_needed in tests/test_augmentations.py to verify:
  • Small images are padded correctly.
  • Large images are NOT cropped (the fix).
  • PadTo still works as expected (legacy behavior).

Verification

Ran tests via Docker:
docker compose run --rm deepforest pytest tests/test_augmentations.py
Result: All 28 tests passed.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.41%. Comparing base (ecf3a1c) to head (a97b9b7).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1296      +/-   ##
==========================================
+ Coverage   87.34%   87.41%   +0.07%     
==========================================
  Files          24       24              
  Lines        2978     2996      +18     
==========================================
+ Hits         2601     2619      +18     
  Misses        377      377              

Flag	Coverage Δ
unittests	87.41% <100.00%> (+0.07%)	⬆️

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[abhayrajjais01]

@henrykironde can you please review and tell me if changes needed??

[ethanwhite]

@abhayrajjais01 - thanks for the contribution, but per our developer guide we want you to engage with us on an issue (and actually hear back from someone; ideally being assigned to the issue) before submitting PRs. @jveitchmichaelis has an opened a WIP PR on this a while ago. You can ask in the original issue if he'd like some help on it and if he says yes then you can proceed.