feat: comprehensive security and architecture improvements

- Add Zod validation schemas with strong password requirements (12+ chars, complexity)
- Implement rate limiting for authentication endpoints (registration, password reset)
- Remove duplicate MetricCard component, consolidate to ui/metric-card.tsx
- Update README.md to use pnpm commands consistently
- Enhance authentication security with 12-round bcrypt hashing
- Add comprehensive input validation for all API endpoints
- Fix security vulnerabilities in user registration and password reset flows

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

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

components/ui/badge.tsx

@@ -1,8 +1,8 @@
-import * as React from "react"
-import { Slot } from "@radix-ui/react-slot"
-import { cva, type VariantProps } from "class-variance-authority"
+import * as React from "react";
+import { Slot } from "@radix-ui/react-slot";
+import { cva, type VariantProps } from "class-variance-authority";
 
-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";
 
 const badgeVariants = cva(
   "inline-flex items-center justify-center rounded-md border px-2 py-0.5 text-xs font-medium w-fit whitespace-nowrap shrink-0 [&>svg]:size-3 gap-1 [&>svg]:pointer-events-none focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px] aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive transition-[color,box-shadow] overflow-hidden",
@@ -23,7 +23,7 @@ const badgeVariants = cva(
       variant: "default",
     },
   }
-)
+);
 
 function Badge({
   className,
@@ -32,7 +32,7 @@ function Badge({
   ...props
 }: React.ComponentProps<"span"> &
   VariantProps<typeof badgeVariants> & { asChild?: boolean }) {
-  const Comp = asChild ? Slot : "span"
+  const Comp = asChild ? Slot : "span";
 
   return (
     <Comp
@@ -40,7 +40,7 @@ function Badge({
       className={cn(badgeVariants({ variant }), className)}
       {...props}
     />
-  )
+  );
 }
 
-export { Badge, badgeVariants }
+export { Badge, badgeVariants };