Add AgentPlane to reference harness implementations

[densmirnov]

Hi - I would like to add AgentPlane to this list.

Disclosure: I maintain AgentPlane.

Why it fits:

AgentPlane is not another coding agent and not a hosted agent platform. It is a local-first, Git-native workflow control layer for repo-local coding-agent work.

It records:

• task state
• accepted plans
• approval state
• verification evidence
• finish / closure records
• Git revision links

Suggested category:

Reference Harness Implementations. AgentPlane is a repo-local harness/control layer around coding-agent work rather than a gateway or model framework, so this category seems closer than a general guardrails section.

Entry added:

AgentPlane - Local-first Git-native CLI harness for auditable coding-agent work with task, plan, verification, and finish records.

Verification:

• python3 scripts/sync_github_metadata.py
• python3 scripts/render_readme.py
• python3 scripts/verify_catalog.py
• git diff --check

Note: this repository's CONTRIBUTING.md asks contributors to run the metadata sync and commit generated README/report files together, so this PR includes the generated star/date snapshot refresh.

Happy to adjust category, wording, or remove if this is outside scope.

[densmirnov]

Quick update: I rebased this branch onto the current main, reapplied the AgentPlane entry through data/projects.yaml, regenerated README.md / README_zh.md, and added the verification report.

Verification now passes with python3 scripts/verify_catalog.py. Happy to adjust the category or wording if another placement fits the list better.