Participant card fields now editable in place (D-style): transparent bg,
underline on hover/focus, no spinners. Covers Initiative, Current HP, Max HP,
and AC badge value.
Click any value to edit. Blur/Enter saves. Escape cancels. Status recomputes
on HP change (conscious/dying/dead/down per ruleset).
Editing overlay: when a field is focused, amber ring highlights the card and
a centered pointer-events-none label shows '✎ Editing {field}'. Label floats
over card middle without blocking input — taps pass through to field.
Handlers: handleInlineCurrentHp (recomputes status), handleInlineMaxHp,
handleInlineAc. Keys prefixed to avoid React key collisions when values match.
Tests: selectors updated to use element id (monsterMaxHp) since inline
aria-labels now match form label queries.