[codex] Complete mechanics package card spine

[8Dionysus]

Summary

• complete the shared mechanics package-card spine for config-projection, diagnostic-spine, federation-seams, governed-execution, machine-fit, and runtime-lifecycle
• add package-local PROVENANCE cards and align DIRECTION, ROADMAP, and LANDING_LOG cards with owner-specific boundaries
• update mechanics route law, the package atlas, changelog, and stack validation so PROVENANCE.md is required for every mechanics package
• record the structural decision in docs/decisions

Validation

• python scripts/validate_stack.py
• python scripts/validate_nested_agents.py
• python scripts/build_diagnostic_surface_catalog.py --check
• python scripts/validate_diagnostic_surface_catalog.py
• git diff --check
• python -m pytest -q

Notes

• No live runtime state, secrets, model artifacts, service lifecycle, or host deployment surfaces were changed.
• Pytest passed with the existing LangChain/Pydantic warning on Python 3.14.