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/lib/utils.ts

@@ -0,0 +1,45 @@
+import { clsx, type ClassValue } from "clsx";
+import { twMerge } from "tailwind-merge";
+
+/**
+ * Merge Tailwind CSS classes with proper precedence
+ */
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}
+
+/**
+ * Format a number as Mexican peso currency
+ */
+export function formatCurrency(amount: number): string {
+  return new Intl.NumberFormat("es-MX", {
+    style: "currency",
+    currency: "MXN",
+    minimumFractionDigits: 0,
+    maximumFractionDigits: 2,
+  }).format(amount);
+}
+
+/**
+ * Format a date in Spanish format (e.g., "15 de enero de 2024")
+ */
+export function formatDate(date: Date | string): string {
+  const dateObj = typeof date === "string" ? new Date(date) : date;
+  return new Intl.DateTimeFormat("es-MX", {
+    day: "numeric",
+    month: "long",
+    year: "numeric",
+  }).format(dateObj);
+}
+
+/**
+ * Format time in 12-hour format with AM/PM
+ */
+export function formatTime(date: Date | string): string {
+  const dateObj = typeof date === "string" ? new Date(date) : date;
+  return new Intl.DateTimeFormat("es-MX", {
+    hour: "numeric",
+    minute: "2-digit",
+    hour12: true,
+  }).format(dateObj);
+}