FieldInput

A single field driven by its kind. It knows no domain — the option set and the translations both come from the caller.

When to use it

You need one field somewhere you control the layout and the label yourself.
You are composing a non-trivial form (sections, side-by-side columns) and want at least consistent input behaviour.
The field is kind: "options" and only that screen knows the option set — supply it through renderOptions.

You are building an ordinary vertical form out of several fields. IngotForm adds the labels and hints and saves you copying them.
You want a field the Ingot does not know (date, file, colour). IngotFieldSpec has a closed set of kind values; a new one is added there, not by working around the primitive.
The form is written by hand and the fields have nowhere to come from — there are three of them and they are fixed. That is IngotField, which carries its own label, hint and error. This primitive is deliberately label-less, because IngotForm composes the label above it.

field: IngotFieldSpec — The field descriptor; kind decides what is rendered.
value: unknown — The current value. The field is controlled.
onChange: (next: unknown) => void — The new value, already coerced according to kind.
testId: string — data-testid of the input. Required — the end-to-end tests hang off it.
disabled: boolean — Locks the input, typically while a mutation is in flight.
className: string — Class applied to the input.
renderOptions: (args) => ReactNode — Picker over a named set. Without it an options field renders as a disabled select holding only the current value.
secretPlaceholder: (field: IngotFieldSpec) => string — Custom secret-field text instead of the IngotProvider dictionary.