Variable default

default: {
    initialize: (this: HiddenStoreContext) => void;
    manipulator: string;
    name: string;
    template: string;
}

initialize: (this: HiddenStoreContext) => void

Stamps on the caller's own class, so several stores on one page stay tellable apart.

A function expression, never shorthand method syntax. Clay serialises a registered component by writing key: followed by the function's own toString, and a shorthand method stringifies with its name attached. That comes out as initialize:initialize() { and stops the whole settings page parsing. Every component on the page shares that fate, so the symptom is a config screen that never opens at all.
manipulator: string
name: string
template: string