Fix Select custom tag align

Editor assessment

The subject states the fix precisely — the Select's custom tag alignment is corrected — naming the component, the element (custom tag), and the CSS concern, so the change is understandable without a diff. The footer `close #28955` is well formed and links the work to its reporting issue, supplying the visual-defect context the absent body would carry. Type `style` is accurate for a CSS-only correction; absent scope is tolerable since Select is named. No body prose exists, acceptable at this size. Style hygiene is clean — no trailing period, no junk. A clear, traceable, publishable small fix.