Curated featured agents — read-only, surfaced by the renderer's "preconfigured" picker. Not full Agent records; minimal display metadata only.
@type t() :: %Spatio.Model.PreconfiguredAgent{ agentId: String.t(), description: String.t() | nil, hasAllTools: boolean() | nil, icon: String.t() | nil, name: String.t(), tagline: String.t() | nil, toolCount: integer() | nil }