Fix NotImplementedError usage in Projector

[MaxGhenis]

Summary

• fix NotImplementedError usage in Projector.transform
• add regression test for Projector base class

Testing

• pytest tests/core/test_projectors.py::test_base_projector_transform_raises -q

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.26%. Comparing base (30facf3) to head (cbd1394).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #367      +/-   ##
==========================================
+ Coverage   84.00%   84.26%   +0.26%     
==========================================
  Files         194      194              
  Lines       10018    10025       +7     
  Branches     1055     1055              
==========================================
+ Hits         8416     8448      +32     
+ Misses       1308     1281      -27     
- Partials      294      296       +2     

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[Copilot]

Pull Request Overview

This PR fixes the usage of NotImplementedError in Projector.transform and adds a regression test to ensure the proper exception is raised.

• Corrected the behavior in Projector.transform to raise NotImplementedError.
• Added a regression test to verify the correct exception behavior.
• Updated the changelog to reflect these changes.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
tests/core/test_projectors.py	Added regression test to verify NotImplementedError is raised in Projector.
policyengine_core/projectors/projector.py	Updated transform to properly raise NotImplementedError.
changelog_entry.yaml	Added changelog entry summarizing this patch.