refactor(hub): migrate dashboard to shadcn components

Replace manual CSS classes with shadcn Card, CardHeader, CardTitle,
CardContent, and Badge components. Remove inline <style> block —
use Tailwind utility classes via shadcn theme tokens. Add Biome
formatting across all components.

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

src/components/ui/scroll-area.tsx

@@ -1,9 +1,9 @@
-"use client"
+"use client";
 
-import * as React from "react"
-import { ScrollArea as ScrollAreaPrimitive } from "@base-ui/react/scroll-area"
+import * as React from "react";
+import { ScrollArea as ScrollAreaPrimitive } from "@base-ui/react/scroll-area";
 
-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";
 
 function ScrollArea({
   className,
@@ -25,7 +25,7 @@ function ScrollArea({
       <ScrollBar />
       <ScrollAreaPrimitive.Corner />
     </ScrollAreaPrimitive.Root>
-  )
+  );
 }
 
 function ScrollBar({
@@ -40,7 +40,7 @@ function ScrollBar({
       orientation={orientation}
       className={cn(
         "flex touch-none p-px transition-colors select-none data-horizontal:h-2.5 data-horizontal:flex-col data-horizontal:border-t data-horizontal:border-t-transparent data-vertical:h-full data-vertical:w-2.5 data-vertical:border-l data-vertical:border-l-transparent",
-        className
+        className,
       )}
       {...props}
     >
@@ -49,7 +49,7 @@ function ScrollBar({
         className="relative flex-1 rounded-full bg-border"
       />
     </ScrollAreaPrimitive.Scrollbar>
-  )
+  );
 }
 
-export { ScrollArea, ScrollBar }
+export { ScrollArea, ScrollBar };