feat(cocoindex-code): mirror upstream ccc skill as Roxabi plugin

[MickaelV0]

Summary

• Mirrors the ccc skill from cocoindex-io/cocoindex-code into the Roxabi marketplace as a new cocoindex-code plugin.
• Skill content (SKILL.md + references/) is copied verbatim from upstream under Apache-2.0 — copyright retained, attribution in plugins/cocoindex-code/README.md.
• The ccc binary itself is not vendored — installed separately via pipx install 'cocoindex-code[full]' or uv tool install cocoindex-code.
• CLI-only path — no MCP server required.

Why

Lets Roxabi users pull AST-based semantic code search from the marketplace they already trust, without adding a second source. Complements the existing gitnexus plugin (graph-based code intel) — cocoindex-code is the embedding-based counterpart.

Companion PR upstream

A draft PR is open on the upstream repo to publish the same skill as a first-class Claude Code marketplace: cocoindex-io/cocoindex-code#161. When that lands, users can switch to /plugin marketplace add cocoindex-io/cocoindex-code directly — both flows install the same skill.

What changed

File	Change
.claude-plugin/marketplace.json	+7 lines — new entry for cocoindex-code after gitnexus
plugins/cocoindex-code/.claude-plugin/plugin.json	new — plugin manifest
plugins/cocoindex-code/skills/ccc/SKILL.md	new — verbatim from upstream
plugins/cocoindex-code/skills/ccc/references/management.md	new — verbatim from upstream
plugins/cocoindex-code/skills/ccc/references/settings.md	new — verbatim from upstream
plugins/cocoindex-code/README.md	new — Apache-2.0 attribution + install recipe

Test plan

• python3 -c "import json; json.load(open('.claude-plugin/marketplace.json'))" — JSON valid (already verified locally)
• Install the upstream binary: uv tool install cocoindex-code (already verified locally — ccc --help shows full subcommand surface, no MCP launched)
• After merge: /plugin marketplace update Roxabi/roxabi-plugins then /plugin install cocoindex-code@roxabi-marketplace
• Trigger phrases work: "search the codebase X", "ccc", /cocoindex-code:ccc

Notes

• License compliance: Apache-2.0 § 4 requires preserving copyright + attribution for derivative works. Done in plugins/cocoindex-code/README.md.
• No CLI / no daemon launched as part of this PR — install is opt-in by users running pipx install separately.

[MickaelV0]

Closing — superseded by hosting the marketplace on a Roxabi-org fork of upstream (Roxabi/cocoindex-code). The fork itself becomes the install source until upstream merges its own marketplace manifest, so the in-tree mirror here is redundant. See cocoindex-io/cocoindex-code#161 for the upstream PR.