fix(web): session-card button overflow + bottom-nav icon alignment

- Dashboard session card: the header stacks the title above the action buttons
  on narrow screens (flex-col -> sm:flex-row) and the button group wraps
  (flex-wrap), so "Request IDR" / "Stop session" no longer overflow the card.
- Mobile bottom nav: give each label a fixed two-line-tall centered box so a
  1- or 2-line label (labels vary by locale) keeps every tab icon at the same
  height.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/routes/index.tsx

@@ -60,12 +60,12 @@ function Dashboard() {
             </div>
 
             <Card>
-              <CardHeader className="flex-row items-center justify-between space-y-0">
+              <CardHeader className="flex flex-col items-start gap-3 space-y-0 sm:flex-row sm:items-center sm:justify-between">
                 <CardTitle className="flex items-center gap-2">
                   <MonitorPlay className="size-4" />
                   {m.status_session()}
                 </CardTitle>
-                <div className="flex gap-2">
+                <div className="flex flex-wrap gap-2">
                   <Button
                     variant="outline"
                     size="sm"