<form-field>

Per-field wrapper for a form control: label, slotted control, and an
optional hint or error message, in one consistent unit repeated across a
form. Purely presentational — composes whatever control is slotted
(form-select, multi-select, autocomplete-input, ui-checkbox, etc.)
without intercepting its events or value.

Set floating-label for supported text controls (input, textarea,
autocomplete-input, address-autocomplete, and text-area). The label
then rests inside an empty field and moves to a smaller top-left position
while focused or non-empty. Other controls keep the external label.

The label wraps the default slot for a best-effort visual/click
association only: every existing value-entry control encapsulates its
real <input> inside its own shadow DOM, so there is no light-DOM id a
for attribute could target from outside, and this component cannot set
aria-describedby/aria-invalid on an arbitrary slotted control's
shadow-encapsulated input for the same reason. The error message uses
role="alert" as the practical accessibility mitigation instead of true
aria-describedby association.