Plan step 19, containment.md C-13, C-23 and the directly actionable card
of C-13/C-18. A card had one elevation and never changed it, and its
hover replaced the elevated card's shadow with the state layer; it now
names its variant in `data-card` and moves a step on hover (elevated
1 to 2, filled and outlined 0 to 1) with the layer over it. The 12 to 16
corner morph on hover is gone: M3 gives a card one shape and lists shape
morph for buttons, FABs and list items only. New `actionable` prop for
M3's directly actionable card — the card is the one tab stop, with
`role="button"` (or `link`), its `title` as the name, and Enter or Space
reaching the opener from resources/js/list-rows.js.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
