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-list-common/priorityDropdown/priority-dropdown.tsx

@@ -153,7 +153,7 @@ const PriorityDropdown = ({ task, teamId }: PriorityDropdownProps) => {
   // Fallback rendering for raw priority values or when priority list is not loaded
   return (
     <div 
-      className="px-2 py-1 text-xs rounded"
+      className="px-2 py-1 text-xs rounded-sm"
       style={{
         backgroundColor: getPriorityColor(task.priority) + ALPHA_CHANNEL,
         borderRadius: 16,

worklenz-frontend/src/components/task-list-common/status-dropdown/status-dropdown.tsx

@@ -128,7 +128,7 @@ const StatusDropdown = ({ task, teamId }: StatusDropdownProps) => {
   // Fallback rendering for raw status values or when status list is not loaded
   return (
     <div 
-      className="px-2 py-1 text-xs rounded"
+      className="px-2 py-1 text-xs rounded-sm"
       style={{
         backgroundColor: getStatusColor(task.status),
         borderRadius: 16,

worklenz-frontend/src/components/task-list-common/task-row/task-row-name/task-row-name.tsx

@@ -52,7 +52,7 @@ const TaskRowName = React.memo(
       return (
         <button
           onClick={() => handleToggleExpansion(taskId)}
-          className="hover flex h-4 w-4 items-center justify-center rounded text-[12px] hover:border hover:border-[#5587f5] hover:bg-[#d0eefa54] transition duration-150"
+          className="hover flex h-4 w-4 items-center justify-center rounded-sm text-[12px] hover:border hover:border-[#5587f5] hover:bg-[#d0eefa54] transition duration-150"
         >
           {expandedTasks.includes(taskId) ? <DownOutlined /> : <RightOutlined />}
         </button>