This introduces Ink.TextField, a styled text input component. It

supports text-like input types (text, search, email, tel, url,

password), placeholder text, form field names, arbitrary attributes, a

disabled state, and an optional leading icon (such as ink-i-search for

search boxes). The type is a TextFieldType union, so types that would

break the field chrome are caught at compile time.
The component is structured as a wrapper element drawing the field

chrome, containing the optional __icon and the native __input. The

input is exposed as an inputEl member, with value, disabled,

placeholder, and autofocus properties proxying to it, plus a

focus() method. Consumers can listen to standard DOM events (input,

change) on the input. Focus and hover styling use

:focus-within/:hover on the wrapper.
Because the wrapper draws the chrome, clicking the padding or the icon

focuses the input. This matches how a native field behaves.
Fields can be given an accessible name through the ariaLabel and

ariaLabelledBy options. This matters most for icon-only search boxes,

where placeholder text is not a reliable label. ariaLabelledBy takes

precedence when both are set.
An initial value is set as an attribute as well as a property, so it

becomes the field's default value. Resetting a containing form now

restores that value instead of blanking the field.
Styling uses the existing input design tokens (--ink-p-input-*,

--ink-g-border-input, --ink-u-border-radius-input) through a new

schema/component/theme triplet. The wrapper pins font-weight and

line-height, the same way Ink.Button does, so a host page cannot

distort the field's height. The input resets its appearance, so browsers

do not draw their own chrome for types such as search.
This is the foundation for a new auto-complete/search component, which

builds on top of this field.

Ran unit tests.
Verified the appearance and default height in Firefox and Chrome,

  including the search-icon configuration. Confirmed that a host page

  setting line-height and font-weight leaves that height unchanged.
Verified that clicking the leading icon focuses the input, and that

  the focus ring is drawn around the wrapper.
Added a new storybook entry and verified appearance in light and dark

  modes.