Add Hamilton integration guide aligned with SDLC phases

[2-Coatl]

Summary

• add an ExecPlan for documenting Hamilton framework adoption across the six SDLC IA phases
• publish the Hamilton integration guide and link it from the documentation index and SDLC agents playbook
• extend the documentation alignment tests with coverage for the new guide

Testing

• python3 -m pytest docs/qa/testing/test_documentation_alignment.py::test_hamilton_framework_integration_doc_is_published

---

Codex Task