Entity preview — accessibility

Keyboard

The card opens on focus as well as on hover (300 ms delay), so tabbing through references in text shows the same information a mouse user gets.
Everything inside is reachable: the clickable values (.eref-hc-act) and the footer (<a> or <button>) are real controls.
The card closes when focus leaves the reference and its card, or when the pointer leaves both. pinned keeps it open while a menu opened from it is up.
Escape is not handled by the card itself; moving focus away closes it.

The card is announced as a dialog-like layer named by ariaLabel (defaulting to the record name), so a screen reader says whose card this is before reading it.
Rows are icon + value with no label text, so the icon must not be the only carrier of meaning: the value has to read on its own ("+420 605 123 456", "Jednání"). This is canon K1 and an accessibility requirement at the same time.
The loading skeleton is decorative; the unavailable state is a sentence in the card, not a role change.
The trigger keeps its own semantics (EntityRef is a button or a link); the card does not change them.

Foundation ring from ds.css on the clickable value and the footer control.
Opening the card does not move focus — the reference keeps it, and Tab then enters the card because it is portalled after the trigger only in DOM order; where it lands depends on the page. (Same portal caveat as Popover.)
The card has no focus trap and does not need one; it is not modal.

Computed from packages/ui/src/tokens/tokens.css:

Name .eref-hc-nm --ink-900 on --surface-100 = 17.59:1 light, 14.53:1 dark.
Row value .eref-hc-cv --fg = 17.59:1 light, 14.53:1 dark.
Row icon .eref-hc-ri and the facts strip --fg-muted = 2.85:1 light, 3.63:1 dark — below AA for text and below the 3:1 non-text minimum in light theme.
unavailable state adds .is-dim, which lowers the whole card further — acceptable only because the state carries no data.
Footer link --accent on --surface-100 = 4.44:1 light, 3.83:1 dark.
Card border: hairline, below the 3:1 non-text minimum; --shadow-pop does the separating.

The facts strip and the row icons sit at 2.85:1 in light theme.
The 300 ms delay plus the hover-out close makes the card hard to use with a tremor or a coarse pointer; there is no click-to-pin from the reference itself.
No touch path: on a phone there is no hover, and the reference opens the record instead.
The card grows with its content — there is no max height and no internal scroll, so an over-filled card can exceed a short viewport.