Register a remote (Streamable HTTP) MCP server in the official MCP Registry with no package

Documented steps

1. Use `remotes[]` instead of `packages[]` when your server is hosted and clients connect over the network rather than installing anything.
2. Write server.json with $schema https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json, `name` in a namespace you can authenticate, `description`, `version`, and remotes: [{"type": "streamable-http", "url": "https://api.example.com/mcp"}]. The legacy value "sse" is also accepted but new servers should use streamable-http.
3. If the endpoint needs per-user configuration, declare it rather than hardcoding it: `headers[]` entries take name, description, isRequired, isSecret, default, choices; URL templating with {variable-name} plus a `variables` block covers tenant-specific hosts.
4. Authenticate for the namespace: `mcp-publisher login github` for io.github.*, or DNS/HTTP auth for your own domain (recommended for a hosted product, since the namespace then matches the brand).
5. Run `mcp-publisher publish`, then verify: curl "https://registry.modelcontextprotocol.io/v0.1/servers?search=<name>" and confirm the remotes[] block round-tripped.
6. Smoke-test what clients will actually do: POST an initialize JSON-RPC request to the advertised URL with `accept: application/json, text/event-stream` and confirm a session is established.