Bugfix: Add ECP Contributions

[wavefunction91]

Closes #446

[Copilot]

Pull request overview

Fixes Hamiltonian construction for systems using effective core potentials (ECPs) by ensuring ECP one-electron contributions (and ECP-adjusted nuclear charges) are incorporated into the AO core Hamiltonian before transforming to the active-space Hamiltonian. This addresses the incorrect/unstable energies reported in issue #446.

Changes:

• Update both the standard and Cholesky Hamiltonian constructors to (1) use the ECP-adjusted internal molecule associated with the internal basis set and (2) add ECP one-electron integrals to H_core.
• Add a Python regression test validating that Mo/def2-svp produces stable, expected one-electron integral magnitudes for both constructors.

Reviewed changes

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

File	Description
python/tests/test_ecp_hamiltonian.py	Adds regression coverage ensuring ECP terms are reflected in returned one-electron integrals.
cpp/src/qdk/chemistry/algorithms/microsoft/hamiltonian.cpp	Uses internal_basis_set->mol (ECP-adjusted charges) and adds ecp_integral into H_full.
cpp/src/qdk/chemistry/algorithms/microsoft/cholesky_hamiltonian.cpp	Mirrors the same ECP handling fixes in the Cholesky-based Hamiltonian constructor.

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