rfc: require reproducible rule evidence envelopes

[DmitrL-dev]

Summary

• Extends the executable, testable catalog-rule proposal in rfc: classify findings and make catalog detection rules executable and testable OpenSecureAIAlliance/RFCs#23 with a reproducible result envelope.
• Binds results to rule, evaluator, configuration, normalization and corpus identities and versions.
• Requires denominator, base rate, execution mode, replay/live status, explicit error states and multi-rule overlap semantics.

Relationship

This is a one-commit follow-up on top of eeee2345:rfc/finding-classification, so the upstream PR can absorb the change without duplicating OpenSecureAIAlliance#23.

Validation

• DCO sign-off present
• git diff --check passes