feat: conform to Agent Plugins spec v1.0.0

[eitanp461]

Makes the plugin conform to the Agent Plugins open standard (v1.0.0).

• Add root plugin.json with the spec $schema. Same metadata as the Claude manifest, without the skills/mcpServers pointers — the spec discovers components by fixed locations (skills/, mcp.json).
• mcp.json: add the required top-level $schema and a type field per server (streamable-http for the /mcp endpoints, sse for analysis).

The existing .claude-plugin/ and .cursor-plugin/ manifests are unchanged; the spec tolerates client-specific extras.

🤖 Generated with Claude Code

[eitanp461]

Value of merging this

• Agent Plugins launched with client support already in place: VS Code, Cursor, GitHub Copilot, ChatGPT/Codex, Kiro and more (compatible clients). One conformant repo works across all of them.
• agentpluginsdirectory.com lists ~1,040 verified plugins, none from Cloudinary. Listing is automatic — a daily crawler finds public repos with a root plugin.json carrying the spec $schema and validates it. Merging this gets Cloudinary listed within a day, no submission step.
• The type fields added to mcp.json also fix a latent Claude Code issue: it skips server entries that have a url but no type.

[eitanp461]

Kiro announces support for Agent plugins - https://kiro.dev/blog/powers-supports-plugins/

[njb90]

Assume the types are all verified as correct, looks good.