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/task-management/task-status-dropdown.tsx

@@ -144,7 +144,7 @@ const TaskStatusDropdown: React.FC<TaskStatusDropdownProps> = ({
           ref={dropdownRef}
           className={`
             fixed min-w-[160px] max-w-[220px] 
-            rounded border backdrop-blur-sm z-[9999]
+            rounded border backdrop-blur-xs z-9999
             ${isDarkMode 
               ? 'bg-gray-900/95 border-gray-600 shadow-2xl shadow-black/50' 
               : 'bg-white/95 border-gray-200 shadow-2xl shadow-gray-500/20'
@@ -185,7 +185,7 @@ const TaskStatusDropdown: React.FC<TaskStatusDropdownProps> = ({
                 >
                   {/* Status Color Indicator */}
                   <div 
-                    className={`w-3 h-3 rounded-full shadow-sm border-2 ${
+                    className={`w-3 h-3 rounded-full shadow-xs border-2 ${
                       isDarkMode ? 'border-gray-800/30' : 'border-white/20'
                     }`}
                     style={{ backgroundColor: getStatusColor(status) }}