shared badge: drop the disclosure chevron

mara, #3757: remove the chevrons. aria-expanded's own outline/bg
stays as the only affordance.

frontend/packages/shared/src/badge/Badge.css

@@ -93,10 +93,6 @@
   /* Fixes badge with emoji having different size. */
   line-height: 1;
 }
-.ui-badge-caret {
-  font-size: 0.75em;
-  color: var(--muted-on-dim);
-}
 /* Blended with `--fg`, not the raw accent — a stylix-fed scheme can pick
    any hue/lightness for `--green`/`--amber`/etc., and nothing guarantees
    an arbitrary accent clears 4.5:1 against `--purple-dim` the way the two

frontend/packages/shared/src/badge/Badge.tsx

@@ -47,9 +47,11 @@ export interface BadgeProps {
   /** Decorative glyph before the label; `aria-hidden`, the text is still the real label. */
   icon?: ComponentChildren;
   /**
-   * Present → renders a `<button>` (real control, min touch target) and
-   * shows a disclosure caret. Absent → renders a plain `<span>` (status
-   * display only, e.g. "alive"/"idle 6m").
+   * Present → renders a `<button>` (real control, min touch target),
+   * `aria-expanded` reflecting `expanded`. Absent → renders a plain
+   * `<span>` (status display only, e.g. "alive"/"idle 6m"). No visible
+   * disclosure caret (mara: "remove the chevrons") — `hover` +
+   * `aria-expanded`'s outline/bg (Badge.css) are the only affordance.
    */
   onClick?: (e: MouseEvent) => void;
   /** Only meaningful with `onClick` — drives the caret direction + `aria-expanded`. */
@@ -89,11 +91,6 @@ export function Badge({
       ) : null}
       {label ? <span class="ui-badge-label">{label}</span> : null}
       <span class="ui-badge-value">{value}</span>
-      {onClick ? (
-        <span class="ui-badge-caret" aria-hidden="true">
-          {expanded ? '▴' : '▾'}
-        </span>
-      ) : null}
     </>
   );
   if (onClick) {