fix: improve mobile terminal region tabs

frontend/components/dashboard/scan-terminal/MobileRegionTabs.tsx

@@ -15,7 +15,7 @@ export function MobileRegionTabs({
   onSelectTab: (key: string) => void;
 }) {
   return (
-    <div className="mobile-region-tabs flex overflow-x-auto border-b border-slate-200 bg-white px-2">
+    <div className="mobile-region-tabs flex min-h-11 snap-x gap-1 overflow-x-auto border-b border-slate-200 bg-white px-2 [-webkit-overflow-scrolling:touch] [scrollbar-width:none]">
       {groups.map((g) => {
         const label = isEn ? g.labelEn : g.labelZh;
         const isActive = activeTab === g.key;
@@ -23,9 +23,10 @@ export function MobileRegionTabs({
           <button
             key={g.key}
             type="button"
+            aria-pressed={isActive}
             onClick={() => onSelectTab(g.key)}
             className={clsx(
-              "shrink-0 px-3 py-2.5 text-xs font-bold whitespace-nowrap border-b-2 transition-colors",
+              "flex min-h-11 shrink-0 snap-start items-center border-b-2 px-3 text-xs font-bold whitespace-nowrap transition-colors",
               isActive
                 ? "border-blue-600 text-blue-700"
                 : "border-transparent text-slate-500 hover:text-slate-700"

frontend/components/dashboard/scan-terminal/__tests__/terminalGridPolicy.test.ts

@@ -36,6 +36,10 @@ export function runTests() {
     path.join(projectRoot, "components", "dashboard", "scan-terminal", "use-scan-terminal-query.ts"),
     "utf8",
   );
+  const mobileRegionTabsSource = fs.readFileSync(
+    path.join(projectRoot, "components", "dashboard", "scan-terminal", "MobileRegionTabs.tsx"),
+    "utf8",
+  );
 
   assert(
     dashboardSource.includes("MAX_TERMINAL_CHARTS = 9"),
@@ -57,6 +61,16 @@ export function runTests() {
       dashboardSource.includes("disableClose={true}"),
     "mobile terminal should render one selected chart and suggest landscape for the full grid",
   );
+  assert(
+    dashboardSource.includes("mobile-region-tabs-shell") &&
+      dashboardSource.includes("handleMobileSelectTab") &&
+      dashboardSource.includes("mobileSelectedRowInActiveGroup") &&
+      dashboardSource.includes("mobileActiveGroup?.rows[0]") &&
+      mobileRegionTabsSource.includes("min-h-11") &&
+      mobileRegionTabsSource.includes("snap-x") &&
+      mobileRegionTabsSource.includes("aria-pressed={isActive}"),
+    "mobile region navigation must stay visible above the landscape hint, remain touch-friendly, and switch the visible chart with the active region",
+  );
   assert(
     !dashboardSource.includes("disableClose={visibleSlots.filter(Boolean).length <= 1}"),
     "desktop chart slots must allow clearing the last visible city so users can close a 1x1 chart",