ME-RV-084 — Real maintainer teams and CODEOWNERS

## Summary
Create real GitHub teams and wire CODEOWNERS for dual-area review.

**Normative:** `12_REGISTRY_GOVERNANCE_ADOPTION.md` (ME-RV-084)

## Scaffolding
- CODEOWNERS path stubs + GOVERNANCE team table (still `@fraware` single-owner).

## Acceptance
- [ ] Org teams created
- [ ] CODEOWNERS uses real teams
- [ ] Trust-path dual-area enforcement

## Blocked
Org admin required to create teams.