docs(release): finalize v1 reviewer contract

[stacknil]

Summary

• finalize v1.0 release-facing docs from draft/readiness wording to release status
• add JSON Schema coverage for the remaining reviewer-facing JSON/JSONL artifacts
• extend schema tests to validate JSONL records and assert full reviewer artifact coverage

v1.0 gate

• python scripts/regenerate_artifacts.py --check passed: 23 committed artifacts matched; 6 visual snapshots smoke-regenerated
• fixed input/output path check passed for 37 committed reviewer paths
• python -m pytest tests/test_evidence_pipeline_schemas.py passed: 3 passed
• docs/v0.6-to-v1-artifact-diff.md documents the additive fourth-to-fifth demo contract change
• docs/release-v1.0.md retains: This is a reviewer-contract release, not a production SIEM.

Validation

• python -m pytest tests/test_reviewer_docs.py tests/test_markdown_links.py passed: 18 passed
• python scripts/regenerate_artifacts.py --check; python -m pytest tests/test_evidence_pipeline_schemas.py; python -m pytest passed: regen OK, 3 schema tests passed, 175 full-suite tests passed
• git diff --check passed with CRLF warnings only
• changed-file privacy/security scan passed with no matches

Boundary

This is a reviewer-contract release, not a production SIEM. No live AWS account, real account ID, production detection claim, SIEM/dashboard/alert routing/case-management, autonomous response, or final incident verdict is added.