feat: add grok plugin support for all plugins

[Ishita-02]

Note

Low Risk
Documentation and Grok plugin metadata only; no changes to signing, transaction, or MCP server logic.

Overview
Adds Grok Build support alongside existing Claude Code packaging for the same five Yield.xyz AgentKit plugins.

A new .grok-plugin/marketplace.json registers the base, builder, Privy, MoonPay, and Robinhood plugins with local paths, metadata, and allowed domains. Each plugin directory gets a .grok-plugin/plugin.json manifest (name, version, description, keywords, logo) so Grok can discover and install them.

README.md and plugins/README.md are updated to describe Grok marketplace setup (~/.grok/config.toml), grok plugin install … --trust, MCP wiring via the plugin or .mcp.json / grok mcp add, and wording is broadened from “Claude-only” to “Claude & Grok” where relevant. No runtime or MCP server code changes in this diff—metadata and docs only.

^{Reviewed by Cursor Bugbot for commit 25418a1. Configure here.}

[cursor]

Risk: low. Approved — Cursor Bugbot and Cursor Security Agent completed successfully with no findings that need human review. No reviewers assigned.

  

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