chore: refactor project structure and clean up unused components

- Updated `TODO.md` to reflect new testing tasks and final structure expectations.
- Simplified TypeScript path mappings in `tsconfig.json` for better clarity.
- Revised business logic separation rules in `.cursor/rules` to align with new directory structure.
- Deleted unused client components and services to streamline the codebase.
- Adjusted import paths in scripts to match the new structure.

src/components/ui/Button.tsx

@@ -0,0 +1,43 @@
+import { ButtonHTMLAttributes, forwardRef } from 'react';
+import { cn } from '@/lib/utils';
+
+interface ButtonProps extends ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: 'primary' | 'secondary' | 'danger' | 'ghost';
+  size?: 'sm' | 'md' | 'lg';
+}
+
+const Button = forwardRef<HTMLButtonElement, ButtonProps>(
+  ({ className, variant = 'primary', size = 'md', ...props }, ref) => {
+    const baseStyles = 'inline-flex items-center justify-center font-mono font-medium transition-all duration-200 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-offset-[var(--background)] disabled:opacity-50 disabled:cursor-not-allowed';
+    
+    const variants = {
+      primary: 'bg-[var(--primary)] hover:bg-[var(--primary)]/80 text-[var(--primary-foreground)] border border-[var(--primary)]/30 shadow-[var(--primary)]/20 shadow-lg hover:shadow-[var(--primary)]/30 focus:ring-[var(--primary)]',
+      secondary: 'bg-[var(--card)] hover:bg-[var(--card-hover)] text-[var(--foreground)] border border-[var(--border)] shadow-[var(--muted)]/20 shadow-lg hover:shadow-[var(--muted)]/30 focus:ring-[var(--muted)]',
+      danger: 'bg-[var(--destructive)] hover:bg-[var(--destructive)]/80 text-white border border-[var(--destructive)]/30 shadow-[var(--destructive)]/20 shadow-lg hover:shadow-[var(--destructive)]/30 focus:ring-[var(--destructive)]',
+      ghost: 'bg-transparent hover:bg-[var(--card)]/50 text-[var(--muted-foreground)] hover:text-[var(--foreground)] border border-[var(--border)]/50 hover:border-[var(--border)] focus:ring-[var(--muted)]'
+    };
+    
+    const sizes = {
+      sm: 'px-3 py-1.5 text-xs rounded-md',
+      md: 'px-4 py-2 text-sm rounded-lg',
+      lg: 'px-6 py-3 text-base rounded-lg'
+    };
+    
+    return (
+      <button
+        className={cn(
+          baseStyles,
+          variants[variant],
+          sizes[size],
+          className
+        )}
+        ref={ref}
+        {...props}
+      />
+    );
+  }
+);
+
+Button.displayName = 'Button';
+
+export { Button };