Tailwind defaults to brand theme

Tailwind ships with a generic color palette, type scale, and spacing system. Most projects start with these defaults and gradually accumulate arbitrary values to match the actual brand. `--tailwind` writes a Tailwind v4 `@theme` CSS file directly, containing only the values observed on the page, so no agent step and no hand-transcription sits between the measurement and the theme. Point it at your CSS entry point to write it into the project, or let it default to output/<domain>/theme.css and review it first. An agent is still useful afterwards, for the part measurement cannot do: deciding which observed color deserves the name primary and which is incidental.