ci: sandbox verification — all CI workflows (BHoM_Engine)

[sakanni]

Purpose

Sandbox end-to-end CI verification PR. Exercises all 11 CI workflows against a full BHoM_Engine repo to confirm the post-BHoMBot migration is working correctly.

Expected workflow coverage

Workflow	Expected outcome
Build	Pass — BHoM_Engine builds against BHoM/BHoM dep
Format	Pass or flag pre-existing format issues
Unit Tests	Pass — .ci/unit-tests/BHoM_Engine_Tests.sln present
Copyright Compliance	Pass or flag pre-existing issues
Code Compliance	Pass or flag pre-existing issues
Documentation Compliance	Pass or flag pre-existing issues
Project Compliance	Pass or flag pre-existing issues
Dataset Compliance	Pass — .ci/Datasets/ present
Dataset Unit Tests	Pass or pre-existing method-null warnings (known sandbox state)
Versioning	Pass — Versioning_Toolkit provides Verify.FromJsonDatasets()
Serialisation	Pass — Verification.sln present in workspace .ci/code/

Do NOT merge — sandbox verification only.