### What happened

The backend accepts `auth_type: "authorization"` for MCP servers (sends the credential verbatim as the `Authorization` header), but neither the **Create** nor **Edit** MCP server UI form exposes it in the auth-type dropdown. It's only reachable via the management API (`POST`/`PUT /v1/mcp/server`).

### Why it matters

Servers that require an `Authorization` header with a scheme other than the presets (`Bearer`/`Basic`/`token`) can't be configured from the UI. Concrete case: **Elastic Kibana Agent Builder MCP** (`/api/agent_builder/mcp`) requires `Authorization: ApiKey <key>`. The UI's `api_key` option sends `X-API-Key: <key>` instead (intentional, per the form's own hint text), so the upstream returns `401`. Only `auth_type: authorization` with the value `ApiKey <key>` works, and that's UI-unreachable.

### Evidence (current `main`)

- Backend enum + Literal accept it: `litellm/types/mcp.py:36` (`authorization = "authorization"`), `:61` (in `MCPAuthType`) - Client builds the header: `litellm/experimental_mcp_client/client.py:435-436` -> `headers["Authorization"] = self._mcp_auth_value` - UI enum missing it: `ui/litellm-dashboard/src/components/mcp_tools/types.tsx…