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/separator.tsx

@@ -1,9 +1,9 @@
-"use client"
+"use client";
 
-import * as React from "react"
-import * as SeparatorPrimitive from "@radix-ui/react-separator"
+import * as React from "react";
+import * as SeparatorPrimitive from "@radix-ui/react-separator";
 
-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";
 
 function Separator({
   className,
@@ -22,7 +22,7 @@ function Separator({
       )}
       {...props}
     />
-  )
+  );
 }
 
-export { Separator }
+export { Separator };