Keep a switch's track whole beside long text in a row

`[data-md-toggle] { min-width: 0 }` let the switch's root shrink below
its 52px track as a flex item. In `<x-row justify="between">` beside a
paragraph, flex shrinking weighs each item by its width, so the root of
a bare switch gave up a share of its 52px, and a switch with a long
label of its own gave its label a column one word wide and less; the
track, which does not shrink inside the root, ran out of it and past a
card's edge on a phone. `<x-checkbox>`'s root did the same with its box.

Both roots now keep their automatic minimum, the control and, beside a
label, its longest word, so the text beside the control, or the
control's own label, wraps instead. The toggle's docblock and the skill
say so.

A browser test lays a bare switch, a labelled switch and a bare
checkbox beside long text in rows on a 393px window and checks each
control's size and that it stays inside its row, and that the switch's
own label wraps inside its root; it fails without the change in Chrome,
Firefox and Safari.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

UPGRADE.md

@@ -68,6 +68,12 @@
   wire:ignore>` holding `<selectedcontent>`, the browser's copy of the chosen option, which
   select.css cuts; a browser without the customizable select never renders it. A test that
   matched a select's markup up to its first `<option>` finds the button there.
+- **A switch beside long text in a row keeps its track.** `<x-toggle>`'s root could shrink to
+  nothing as a flex item, so beside a paragraph in `<x-row justify="between">`, or with a long
+  label of its own, the 52px track ran out of the row and past a card's edge on a phone.
+  `<x-checkbox>` did the same with its box. Both roots now keep their automatic minimum — the
+  control, and beside a label its longest word — so the text wraps instead. A `flex: none` an
+  application put on the switch to hold it can go.
 
 ## From 2.0.0 to 2.1.0