608c3840ca
Add lean, native plugin-install entry points so each harness's own plugin manager can install this marketplace (mirroring obra/superpowers) — committing only small JSON registries, not duplicated skill/agent content trees. - Codex: committed marketplace registry (.agents/plugins/marketplace.json) + per-plugin manifests (plugins/*/.codex-plugin/plugin.json). Entries point at source ./plugins/<name>; Codex reads SKILL.md directly. Transformed .codex/skills|agents stay gitignored. - Cursor: commit the existing .cursor-plugin/ marketplace + .cursor/rules/ (these already point at source plugins/). - Gemini: gemini-extension.json already committed (contextFileName: AGENTS.md); transformed trees stay gitignored (install via clone + make generate). - OpenCode: unchanged — install via `make install-opencode` (transformed tree stays gitignored). - CLAUDE.md is now a symlink to AGENTS.md; Claude-Code addenda moved to docs/harnesses.md. - CI: new step fails if `make generate-all` drifts from the committed registries. Net new committed: ~720 KB of manifests (no skill/agent duplication). Adds round-trip tests for the new registries + the symlink. Docs updated across README, docs/harnesses.md, ARCHITECTURE.md, CONTRIBUTING.md, GEMINI.md, docs/authoring.md, and the PR template.