<x-checkbox> renders data-md-checkbox, its box, tick and dash, and its
row, text and errors as data-md-* attributes; the 18px tick takes a size
prop and a label-less box md-touch-target (plan step 36). selection.css
moves into material.components as the row, text and state layer the
three controls share, and each control's drawing goes to its own file:
checkbox.css, radio.css, toggle.css, on the state tokens. The radio and
the switch take the renamed shared hooks now and lose their layout
classes in their own commits. field.js follows data-md-indeterminate.
Renaming the switch's data-handle also stops selection.css matching the
slider's handles, which it drew 24px above the track.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
