Add an icon to the calendar module title for visual consistency

Add the Calendar icon component next to the title in the Calendar page header, improving visual alignment with other modules.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: b163d4c0-de5e-4f4e-a9c0-aed4c7049718
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/b163d4c0-de5e-4f4e-a9c0-aed4c7049718/ByygiiM

client/src/pages/Calendar.tsx

@@ -182,6 +182,8 @@ export default function Calendar() {
       {/* Header */}
       <div className="bg-white shadow-sm border-b border-gray-200 p-6">
         <div className="flex items-center justify-between">
+          <div className="flex items-center">
+            <Calendar className="w-8 h-8 text-blue-600 mr-3" />
             <div>
               <h2 className="text-2xl font-bold text-gray-900">
                 Calendrier des Commandes & Livraisons
@@ -190,6 +192,7 @@ export default function Calendar() {
                 {format(currentDate, 'MMMM yyyy', { locale: fr })}
               </p>
             </div>
+          </div>
           <div className="flex items-center space-x-4">
             {/* Legend */}
             <div className="flex items-center space-x-6 text-sm">