feat: publish MCP server to registry

[jonathannorris]

• Add server.json for remote-only server:
  • name: com.devcycle/mcp
  • remotes: https://mcp.devcycle.com/mcp and https://mcp.devcycle.com/sse
  • repository and website_url metadata
• Add schema validation:
  • yarn validate:server using Ajv
  • cache schema in .schema/ and ignore via .gitignore
• Update CI (.github/workflows/cli-release.yml):
  • install mcp-publisher
  • sync only .version in server.json to tag
  • DNS login using MCP_KEY from AWS Secrets (DEVCYCLE_GITHUB_MCP_REGISTRY_PKEY)
  • publish to MCP Registry
• Remove package-based install from server.json (remote only for now)

Notes

• Secret required: DEVCYCLE_GITHUB_MCP_REGISTRY_PKEY (64‑hex Ed25519 private key seed)
• Validation: yarn validate:server passes
• Registry entry: curl "https://registry.modelcontextprotocol.io/v0/servers?search=com.devcycle/mcp"
• Publish MCP registry instructions: https://github.com/modelcontextprotocol/registry/blob/main/docs/guides/publishing/publish-server.md