feat(frontend): Complete shadcn/ui migration with dark mode support and analytics updates.

- Convert all analytics components to use shadcn Card and semantic colors
- Update RawTransactionModal with proper shadcn styling and theme support
- Fix all remaining hardcoded colors to use CSS variables (bg-card, text-foreground, etc.)
- Ensure consistent theming across light/dark modes for all components
- Add custom tooltips with semantic colors for chart components

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/components/ui/alert.tsx

@@ -0,0 +1,59 @@
+import * as React from "react";
+import { cva, type VariantProps } from "class-variance-authority";
+
+import { cn } from "@/lib/utils";
+
+const alertVariants = cva(
+  "relative w-full rounded-lg border p-4 [&>svg~*]:pl-7 [&>svg+div]:translate-y-[-3px] [&>svg]:absolute [&>svg]:left-4 [&>svg]:top-4 [&>svg]:text-foreground",
+  {
+    variants: {
+      variant: {
+        default: "bg-background text-foreground",
+        destructive:
+          "border-destructive/50 text-destructive dark:border-destructive [&>svg]:text-destructive",
+      },
+    },
+    defaultVariants: {
+      variant: "default",
+    },
+  },
+);
+
+const Alert = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement> & VariantProps<typeof alertVariants>
+>(({ className, variant, ...props }, ref) => (
+  <div
+    ref={ref}
+    role="alert"
+    className={cn(alertVariants({ variant }), className)}
+    {...props}
+  />
+));
+Alert.displayName = "Alert";
+
+const AlertTitle = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLHeadingElement>
+>(({ className, ...props }, ref) => (
+  <h5
+    ref={ref}
+    className={cn("mb-1 font-medium leading-none tracking-tight", className)}
+    {...props}
+  />
+));
+AlertTitle.displayName = "AlertTitle";
+
+const AlertDescription = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLParagraphElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn("text-sm [&_p]:leading-relaxed", className)}
+    {...props}
+  />
+));
+AlertDescription.displayName = "AlertDescription";
+
+export { Alert, AlertTitle, AlertDescription };