docs(review): align v1 contract stabilization language

[stacknil]

Summary

• align current reviewer docs on the v1 reviewer contract stabilization phase
• replace stale v0.7 / v1.0 consolidation wording in README, docs index, reviewer pack, reviewer brief, and architecture docs
• add a reviewer-doc regression test so current docs keep the closed-demo-expansion language

Validation

• pytest tests/test_reviewer_docs.py tests/test_markdown_links.py
• pytest
• git diff --check

Safety

• docs/test-only change
• no new demo surface
• privacy scan on touched files found no sensitive patterns