feat: Major UI enhancement with BlackRoad brand system

- Add stunning landing page with hero, features, and CTA sections
- Update login/signup pages with dark theme and brand gradients
- Enhance Sidebar with improved navigation and brand colors
- Update AppHeader with search bar, notifications, and user menu
- Add reusable UI components (Button, Card, Input, Badge)
- Add API health and status endpoints
- Apply official BlackRoad brand colors (#FF1D6C hot pink, #F5A623 amber, #2979FF electric blue, #9C27B0 violet)

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

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

components/ui/Badge.tsx

@@ -0,0 +1,42 @@
+import { ReactNode } from 'react';
+import { cn } from '@/lib/cn';
+
+interface BadgeProps {
+  children: ReactNode;
+  variant?: 'default' | 'success' | 'warning' | 'error' | 'info';
+  size?: 'sm' | 'md';
+  className?: string;
+}
+
+export default function Badge({
+  children,
+  variant = 'default',
+  size = 'md',
+  className,
+}: BadgeProps) {
+  const variants = {
+    default: 'bg-white/10 text-gray-300 border-white/20',
+    success: 'bg-emerald-500/10 text-emerald-400 border-emerald-500/20',
+    warning: 'bg-amber-500/10 text-amber-400 border-amber-500/20',
+    error: 'bg-red-500/10 text-red-400 border-red-500/20',
+    info: 'bg-[#2979FF]/10 text-[#2979FF] border-[#2979FF]/20',
+  };
+
+  const sizes = {
+    sm: 'px-2 py-0.5 text-xs',
+    md: 'px-2.5 py-1 text-sm',
+  };
+
+  return (
+    <span
+      className={cn(
+        'inline-flex items-center font-medium rounded-full border',
+        variants[variant],
+        sizes[size],
+        className
+      )}
+    >
+      {children}
+    </span>
+  );
+}