v3.10.0: Agent Plugins Standard

Agent Plugins standard adoption

COG now conforms to the Agent Plugins specification 1.0.0, the open, vendor-neutral plugin format governed by a Technical Steering Committee with representatives from Amazon, Cursor, Microsoft, OpenAI, and Vercel. Any standard-conformant client can load COG as a plugin directly from a checkout.

• plugin.json at the repo root: the standard manifest, validated against the published 1.0.0 schema.
• skills/ at the repo root: generated mirror of .claude/skills/ (the spec's fixed skill location; skills follow the Agent Skills format). .claude/skills/ stays canonical: regenerate with ./scripts/build-agent-plugin.sh, never edit skills/ by hand.
• scripts/build-agent-plugin.sh: one-command mirror rebuild, wired into cog-update.sh so framework updates regenerate the surface automatically.
• Validator coverage: validate-agent-surface.sh now checks the manifest declares the 1.0.0 schema, the mirror matches .claude/skills/ exactly, and the version is aligned across all four packaging manifests.

Also included: v3.9.0 Antigravity surface

v3.9.0 shipped to main but was never tagged, so this release also carries it: a full native Antigravity surface (agy CLI + IDE) with all 33 skills and 10 agents as pointer stubs in .agents/, delegating to the .claude/ playbooks which stay authoritative.

Full detail in CHANGELOG.md.