feat(ui): spring the active pill in tab strips

Give the active-pill tab strips the lifted, physical feel of a spring
capsule: the pill now travels with a slight overshoot instead of jumping,
leans toward a neighbouring tab on press, and sits on a raised surface with
a soft ambient shadow rather than a hard border.

Transitions are opt-in per switch so first measurement and container
resizes still snap into place, and reduced-motion disables them.

Also drop the icons from the git commit/update/pr switcher, along with the
now-unused iconOnlyActiveTab prop.

packages/ui/src/components/views/GitView.tsx

@@ -618,9 +618,9 @@ export const GitView: React.FC<GitViewProps> = ({ isActive }) => {
   const [gitLogDialogMode, setGitLogDialogMode] = React.useState<GitLogDialogMode | null>(null);
 
   const actionTabItems = React.useMemo(() => [
-    { id: 'commit', label: t('gitView.tabs.commit'), icon: <Icon name="git-commit" className="h-3.5 w-3.5" /> },
-    { id: 'branch', label: t('gitView.tabs.update'), icon: <Icon name="git-merge" className="h-3.5 w-3.5" /> },
-    { id: 'pr', label: t('gitView.tabs.pr'), icon: <Icon name="git-pull-request" className="h-3.5 w-3.5" /> },
+    { id: 'commit', label: t('gitView.tabs.commit') },
+    { id: 'branch', label: t('gitView.tabs.update') },
+    { id: 'pr', label: t('gitView.tabs.pr') },
   ], [t]);
   const [actionTab, setActionTab] = React.useState<ActionTab>(() => {
     if (typeof window === 'undefined') {

packages/ui/src/components/views/git/GitHeader.tsx

@@ -374,7 +374,6 @@ export const GitHeader: React.FC<GitHeaderProps> = ({
               onSelect={onSelectActionTab}
               layoutMode="fit"
               variant="active-pill"
-              iconOnlyActiveTab={true}
               activePillButtonClassName="h-7"
               className="h-full"
             />