feat(boss-dashboard): add time tab bar (Today / Week / Month)

src/app/(mobile)/m/dashboard-view.tsx

@@ -95,9 +95,24 @@ export default function BossDashboardView() {
         </button>
       </header>
 
-      {/* Placeholder for tabs (Task 10) */}
-      <div className="rounded-xl bg-muted/30 p-3 text-xs text-muted-foreground">
-        Tabs land here in Task 10.
+      {/* Time tab bar */}
+      <div className="flex gap-1 rounded-xl bg-muted/30 p-1" role="tablist">
+        {(["today", "week", "month"] as const).map((w) => (
+          <button
+            key={w}
+            type="button"
+            role="tab"
+            aria-selected={window === w}
+            onClick={() => setWindow(w)}
+            className={`flex-1 rounded-lg px-3 py-2 text-sm font-medium capitalize transition-colors ${
+              window === w
+                ? "bg-cyan-500/15 text-cyan-300"
+                : "text-muted-foreground hover:text-foreground"
+            }`}
+          >
+            {w}
+          </button>
+        ))}
       </div>
 
       {/* Placeholder for order totals (Task 11) */}