docs/rfcs/RFC-AI-0005.md: status self-contradicts — says "Proposed" and "implemented in the same change set"

[rbowen]

What should happen

1. Update the RFC status to "Implemented" (it says so itself).
2. Add contract:change-request to the Axis 2 table — it exists in the validator and docs/labels-and-capabilities.md but is absent from the RFC table.

Why

The status line contradicts the next sentence. The missing axis entry means the taxonomy RFC is incomplete vs. what's actually enforced.

Which layer

Cross-cutting (RFC, AGENTS.md, sandbox, privacy-LLM)