Expose peer approval tools for blog publishing

[acedatacloud-dev]

Summary

• Add explicit approve and withdraw tools for editorial blog drafts. Approval sends the reviewed review_version and uses the existing confirmation preview.
• Explain that authors cannot approve their own drafts, publishers cannot be the reviewer, and content edits revoke approval.
• Update the operation contract, generated tool snapshot, and README references.

Validation

• python -m pytest tests -q --disable-warnings — 148 passed in an isolated environment with respx 0.22.0.
• python scripts/sync_contract_docs.py --check — current.

Dependency and rollout

• Requires backend approval API and migration in https://github.com/AceDataCloud/PlatformBackend/pull/2093. Release MCP clients after the backend.
• If rollback is required, stop offering the new approval tools while retaining the backend publication gate.

Review

• Adversarial review was not requested. CI passed; human review is pending.