Declare TRACE integration roles and conformance claims

[imran-siddique]

What changed

• adds explicit TRACE roles: record producer, record consumer, or external evidence source
• requires every TRACE integration to declare its role
• requires producers and consumers to declare their conformance level
• classifies all current manifests without forcing external evidence sources to claim record conformance
• adds schema regression tests

Why

integrates_with: trace previously conflated emitting records, verifying records, and supplying evidence that another system may map into TRACE. The schema documentation said conformance was required for emitters/consumers but did not enforce it.

Validation

• all current manifests validate
• python -m pytest tests/test_integration_schema.py -q — 3 passed
• git diff --check