What this PR does / why we need it:

Online serving drops python mode on demand feature views when full_feature_names=True.

store.get_online_features(
    entity_rows=[{"driver_id": 1001}],
    features=["driver_hourly_stats:conv_rate", "python_view:conv_rate_plus_acc"],
    full_feature_names=True,
)
# -> {"driver_id": [...], "driver_hourly_stats__conv_rate": [...]}
#    python_view__conv_rate_plus_acc is missing, no error raised

In _augment_response_with_on_demand_transforms, a full-name request looks for "<view>__<feature>". The pandas path gets that name because transform_arrow renames its outputs. The python path uses transform_dict, which returns the UDF's short output names. Nothing matches, so selected_subset is empty and the feature disappears from the response. Batch and singleton=True python ODFVs are both affected. A model client that asks for full names gets a KeyError or a silently missing input, and the same request in pandas mode works.

The fix renames python mode outputs to odfv._get_projected_feature_name(...) when full_feature_names is set, which matches what _postprocess_arrow_table does for pandas. The declared schema type is also looked up under the full name. Without that, full-name values fell back to type inference instead of the declared dtype.

Which issue(s) this PR fixes:

No existing issue. I searched open issues and PRs for full_feature_names with python mode or ODFVs and didn't find a match.

Checks

• I've made sure the tests are passing.
• My commits are signed off (git commit -s)
• My PR title follows conventional commits format

Testing Strategy

• Unit tests
• Integration tests
• Manual tests
• Testing is not required for this change

New test_python_views_with_full_feature_names in tests/unit/test_on_demand_python_transformation.py. It requests a pandas ODFV, a batch python ODFV and a singleton python ODFV with full_feature_names=True.

• On master (3667772) it fails: only pandas_view__conv_rate_plus_acc_pandas is returned, and both python outputs are missing.
• With this change it passes.
• The ODFV, feature service, online response, versioning and feature store unit files (17 files) give 231 passed. The same 5 tests fail with and without the change: three TestOnDemandTransformationsWithWrites tests hit the UDF globals NameError tracked in On-demand feature view UDFs lose their module globals when rebuilt from the registry, so serving fails with NameError #6815, and two tensor tests need torch.
• ruff check, ruff format --check and mypy feast/utils.py are clean.

Misc

This change was prepared with an AI coding assistant, and the tests and checks above were run locally.