Proposal: add an Agent Plugins 1.0 package

[777genius]

Problem

Supabase MCP documents several client-specific setup flows for the same official hosted endpoint. Agent Plugins 1.0 defines a portable package boundary that compatible clients can reuse.

Proposed scope

I would like to add a small agent-plugin/ package with:

• plugin.json for package identity
• mcp.json pointing only to the documented https://mcp.supabase.com/mcp endpoint
• no runtime code, dependency, OAuth behavior, permission, or default behavior changes
• a short optional README example: npx universal-agent-plugins add supabase

The package would remain useful without that installer because compatible clients can read the standard files directly.

Preflight evidence

I prepared the package locally before opening this issue:

• Agent Plugins 1.0 schema validation passes
• add, info, update, and remove pass in isolated synthetic profiles for Codex, Cursor, Kiro, Gemini CLI, OpenCode, Cline, Windsurf, and VS Code
• the official endpoint returns the expected OAuth-protected 401 response and resource metadata when called without credentials
• no OAuth login, credential, database operation, or real user profile was used

Per the contribution policy, I am asking before submitting the change. If this scope fits the project, may I prepare the PR and be assigned to this issue?