chore(dependencies): update Tailwind CSS and related packages for improved styling

- Added @tailwindcss/postcss as a new dependency.
- Updated tailwindcss to version 4.1.11 for enhanced features and performance.
- Upgraded prettier-plugin-tailwindcss to version 0.6.13 for better formatting support.
- Adjusted postcss.config.js to use the new Tailwind CSS plugin structure.
- Removed the obsolete tailwind.config.js file as it is no longer needed.

worklenz-frontend/src/components/Button.tsx

@@ -24,7 +24,7 @@ const Button: React.FC<ButtonProps & React.ButtonHTMLAttributes<HTMLButtonElemen
   type = 'button',
   ...props 
 }) => {
-  const baseClasses = `inline-flex items-center justify-center font-medium transition-colors duration-200 focus:outline-none focus:ring-2 ${isDarkMode ? 'focus:ring-blue-400' : 'focus:ring-blue-500'} focus:ring-offset-1 ${disabled ? 'opacity-50 cursor-not-allowed' : 'cursor-pointer'}`;
+  const baseClasses = `inline-flex items-center justify-center font-medium transition-colors duration-200 focus:outline-hidden focus:ring-2 ${isDarkMode ? 'focus:ring-blue-400' : 'focus:ring-blue-500'} focus:ring-offset-1 ${disabled ? 'opacity-50 cursor-not-allowed' : 'cursor-pointer'}`;
   
   const variantClasses = {
     text: isDarkMode 
@@ -42,7 +42,7 @@ const Button: React.FC<ButtonProps & React.ButtonHTMLAttributes<HTMLButtonElemen
   };
   
   const sizeClasses = {
-    small: 'px-2 py-1 text-xs rounded',
+    small: 'px-2 py-1 text-xs rounded-sm',
     default: 'px-3 py-2 text-sm rounded-md',
     large: 'px-4 py-3 text-base rounded-lg'
   };