[matouskozak]

Correct native 64-bit parameter widths and pass the actual row count during dataset creation. Add regression tests for feature filtering and model serialization.

Part of #7685. This does not add ARM64 NuGet assets.

Validated on macOS ARM64 using a manually supplied LightGBM 4.6.0 binary. Linux/Windows ARM64 and x64 validation remain pending.

[codecov]

Codecov Report

❌ Patch coverage is 95.89041% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 70.82%. Comparing base (cd2fbd6) to head (daaa53d).
⚠️ Report is 67 commits behind head on main.

Files with missing lines	Patch %	Lines
...osoft.ML.Tests/TrainerEstimators/TreeEstimators.cs	95.58%	0 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7863      +/-   ##
==========================================
+ Coverage   69.76%   70.82%   +1.06%     
==========================================
  Files        1486     1421      -65     
  Lines      275790   280076    +4286     
  Branches    28199    27625     -574     
==========================================
+ Hits       192400   198369    +5969     
+ Misses      75933    73541    -2392     
- Partials     7457     8166     +709     

Flag	Coverage Δ
Debug	70.82% <95.89%> (+1.06%)	⬆️
production	64.25% <100.00%> (+0.31%)	⬆️
test	90.78% <95.58%> (+0.98%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/Microsoft.ML.LightGbm/LightGbmTrainerBase.cs	80.35% <100.00%> (-0.21%)	⬇️
...rc/Microsoft.ML.LightGbm/WrappedLightGbmBooster.cs	90.04% <100.00%> (-0.44%)	⬇️
...rc/Microsoft.ML.LightGbm/WrappedLightGbmDataset.cs	74.21% <100.00%> (ø)
.../Microsoft.ML.LightGbm/WrappedLightGbmInterface.cs	87.71% <ø> (ø)
...osoft.ML.Tests/TrainerEstimators/TreeEstimators.cs	98.05% <95.58%> (+0.20%)	⬆️

... and 498 files with indirect coverage changes

🚀 New features to boost your workflow:

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