PR Template - Sprint 23 Task 07

Task

Add federation smoke test suite.

Summary

• Added Sprint 23 QA suite validating gateway-only dispatch and legacy path removal signals.

Scope

• tests/qa/test_sprint23_federation_channel_qa.py

Validation

• PYTHONPATH=src .venv/bin/pytest -q tests/qa/test_sprint23_federation_channel_qa.py