Add functionality to display scheduled posts and indicate upcoming features

Implement a calendar view to display scheduled posts, and modify AI chat buttons to show "Coming Soon" notifications.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ae4037a0-2a6f-4530-9bac-79b543286bda
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/397bca8c-984f-43ff-841a-10897aeb8140/ae4037a0-2a6f-4530-9bac-79b543286bda/vhNnBGJ

client/src/components/media-upload.tsx

@@ -48,7 +48,7 @@ export default function MediaUpload() {
     }
   }, []);
 
-  const { getRootProps, getInputProps, isDragActive } = useDropzone({
+  const { getRootProps, getInputProps, isDragActive, open } = useDropzone({
     onDrop,
     accept: {
       "image/*": [".png", ".jpg", ".jpeg", ".gif"],
@@ -76,7 +76,10 @@ export default function MediaUpload() {
             Ajoutez des photos ou vidéos, elles seront automatiquement recadrées pour Facebook et Instagram
           </p>
         </div>
-        <Button data-testid="button-browse">
+        <Button 
+          onClick={open}
+          data-testid="button-browse"
+        >
           <CloudUpload className="w-4 h-4 mr-2" />
           Parcourir
         </Button>