PR Template - Sprint 21 Task 01

Task

Enforce canonical JSON serialization for manifests.

Summary

• Added canonical serializer utility and manifest-level canonical JSON output.

Scope

• src/pkg/orchestrator/manifest.py
• tests/unit/test_orchestrator_manifest.py

Validation

• PYTHONPATH=src .venv/bin/pytest -q tests/unit/test_orchestrator_manifest.py -k canonical