feat: Optimize builds, add rollback script, and improve security

Build Optimizations:
- Enable Docker BuildKit cache for faster builds (7min → 3-4min)
- Add .dockerignore to reduce build context
- Optimize Dockerfile with better layer caching
- Run linting and tests in parallel
- Skip blocking checks for dev deployments

Rollback Functionality:
- Add rollback.sh script to restore previous versions
- Supports both production and dev environments
- Automatic health checks after rollback

Security Improvements:
- Add authentication to n8n/generate-image endpoint
- Add rate limiting to all n8n endpoints (10-30 req/min)
- Create email obfuscation utilities
- Add ObfuscatedEmail React component
- Document security best practices

Files:
- .dockerignore - Faster builds
- scripts/rollback.sh - Rollback functionality
- lib/email-obfuscate.ts - Email obfuscation utilities
- components/ObfuscatedEmail.tsx - React component
- SECURITY_IMPROVEMENTS.md - Security documentation

components/ObfuscatedEmail.tsx

@@ -0,0 +1,31 @@
+'use client';
+
+import React from 'react';
+import { obfuscateEmail, deobfuscateEmail } from '@/lib/email-obfuscate';
+
+interface ObfuscatedEmailProps {
+  email: string;
+  children?: React.ReactNode;
+  className?: string;
+}
+
+export function ObfuscatedEmail({ email, children, className }: ObfuscatedEmailProps) {
+  const obfuscated = obfuscateEmail(email);
+  
+  return (
+    <a
+      href="#"
+      data-email={obfuscated}
+      className={className || "obfuscated-email"}
+      onClick={(e) => {
+        e.preventDefault();
+        const link = e.currentTarget;
+        const decoded = deobfuscateEmail(obfuscated);
+        link.href = `mailto:${decoded}`;
+        window.location.href = link.href;
+      }}
+    >
+      {children || email}
+    </a>
+  );
+}