import ods/xls en + de csv

fix modal behavior on close, fine tune import file modal

src/components/AddParticipantModal.tsx

@@ -58,8 +58,18 @@ export default function AddParticipantModal({ isOpen, onClose, onSuccess, campai
     }));
   };
 
+  const handleClose = () => {
+    setFormData({
+      first_name: '',
+      last_name: '',
+      email: ''
+    });
+    setError('');
+    onClose();
+  };
+
   return (
-    <Dialog open={isOpen} onOpenChange={onClose}>
+    <Dialog open={isOpen} onOpenChange={handleClose}>
       <DialogContent className="sm:max-w-[500px]">
         <DialogHeader>
           <DialogTitle>Ajouter un participant</DialogTitle>
@@ -115,7 +125,7 @@ export default function AddParticipantModal({ isOpen, onClose, onSuccess, campai
           </div>
           
           <DialogFooter>
-            <Button type="button" variant="outline" onClick={onClose}>
+            <Button type="button" variant="outline" onClick={handleClose}>
               Annuler
             </Button>
             <Button type="submit" disabled={loading}>