Add unit tests and GitHub Actions CI workflow

[gregorkrz]

Summary

Adds a comprehensive test suite (87 unit tests) and a GitHub Actions CI workflow for automated testing on every push/PR to main.

Tests added (tests/)

Module	Tests	What's covered
test_jetfinder.py	20	PseudoJet properties/addition, NPHistory, NPPseudoJets, anti-kt jet finding, Lorentz/cosine distance matrices, HDBSCAN clustering
test_object_cond.py	30	calc_eta_phi, huber loss, safe_index, assert_no_nans, isin, reincrementalize, get_clustering_np/get_clustering, scatter_counts_to_indices
test_dataset.py	18	spherical_to_cartesian, renumber_clusters, TensorCollection, to_tensor, EventPFCands kinematics
test_utils.py	11	get_path with env vars/fallback, import_module with temp files

GitHub Actions CI (.github/workflows/tests.yml)

• Triggers on push/PR to main
• Python 3.10, CPU-only PyTorch 2.5.0
• Installs all dependencies (matching the Dockerfile approach)
• Runs ruff check --select E9,F63,F7,F82 for syntax/fatal errors
• Runs pytest tests/ -v --tb=short

Also includes

• AGENTS.md with Cursor Cloud development environment instructions

Local test run

All 87 tests pass:

============================== 87 passed in 1.50s ==============================

  

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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^{Reviewed by Cursor Bugbot for commit ca19d05. Configure here.}

[cursor]

CI ruff check missing F82 undefined-name rule

Medium Severity

The ruff check command in the CI workflow is missing the F82 rule from its --select argument. This means the CI won't catch NameError-class bugs (e.g., undefined names), which are valuable lint checks that were intended for enforcement.

 

^{Reviewed by Cursor Bugbot for commit ca19d05. Configure here.}

[cursor]

Unused imports of untested functions in test file

Low Severity

inclusive_jets and add_step_to_history are imported from src.jetfinder.basicjetfinder but never used in any test. This creates the misleading impression that these functions have dedicated test coverage when they don't (they're only exercised indirectly via basicjetfinder).

 

^{Reviewed by Cursor Bugbot for commit ca19d05. Configure here.}