feat(ui): add shadcn/ui base components

- Add clsx, tailwind-merge, class-variance-authority dependencies
- Add Radix UI primitives (dialog, dropdown-menu, label, select, tabs, toast, slot)
- Add lucide-react for icons
- Create components.json for shadcn/ui configuration
- Create lib/utils.ts with cn(), formatCurrency(), formatDate(), formatTime()
- Create Button component with variants (default, destructive, outline, secondary, ghost, link, accent)
- Create Input component with focus ring styling
- Create Card components (Card, CardHeader, CardTitle, CardDescription, CardContent, CardFooter)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/web/components/ui/card.tsx

@@ -0,0 +1,79 @@
+import * as React from "react";
+
+import { cn } from "@/lib/utils";
+
+const Card = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn(
+      "rounded-lg border border-primary-200 bg-white text-primary-900 shadow-sm",
+      className
+    )}
+    {...props}
+  />
+));
+Card.displayName = "Card";
+
+const CardHeader = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn("flex flex-col space-y-1.5 p-6", className)}
+    {...props}
+  />
+));
+CardHeader.displayName = "CardHeader";
+
+const CardTitle = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLHeadingElement>
+>(({ className, ...props }, ref) => (
+  <h3
+    ref={ref}
+    className={cn(
+      "text-2xl font-semibold leading-none tracking-tight text-primary-800",
+      className
+    )}
+    {...props}
+  />
+));
+CardTitle.displayName = "CardTitle";
+
+const CardDescription = React.forwardRef<
+  HTMLParagraphElement,
+  React.HTMLAttributes<HTMLParagraphElement>
+>(({ className, ...props }, ref) => (
+  <p
+    ref={ref}
+    className={cn("text-sm text-primary-500", className)}
+    {...props}
+  />
+));
+CardDescription.displayName = "CardDescription";
+
+const CardContent = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div ref={ref} className={cn("p-6 pt-0", className)} {...props} />
+));
+CardContent.displayName = "CardContent";
+
+const CardFooter = React.forwardRef<
+  HTMLDivElement,
+  React.HTMLAttributes<HTMLDivElement>
+>(({ className, ...props }, ref) => (
+  <div
+    ref={ref}
+    className={cn("flex items-center p-6 pt-0", className)}
+    {...props}
+  />
+));
+CardFooter.displayName = "CardFooter";
+
+export { Card, CardHeader, CardFooter, CardTitle, CardDescription, CardContent };