Style "Add Affiliate" button

Apply the same styling to the "Add Affiliate" button as the other buttons in the `AffiliatesList` component.

Author: lovable-dev[bot]

src/components/AffiliatesList.tsx

@@ -156,15 +156,15 @@ export const AffiliatesList = ({ campaignId, onCopyTrackingLink }: AffiliatesLis
                   variant="outline" 
                   size="sm"
                   onClick={() => handleEditAffiliate(affiliate)}
-                  className="h-8 w-8 p-0"
+                  className="h-8 w-8 p-0 border-slate-300 rounded-xl"
                 >
                   <Edit2 className="h-3 w-3" />
                 </Button>
                 <Button 
                   variant="outline" 
                   size="sm"
                   onClick={() => handleCopyTrackingLink(affiliate.id)}
-                  className="h-8 px-3"
+                  className="h-8 px-3 border-slate-300 rounded-xl"
                 >
                   <Copy className="h-3 w-3 mr-2" />
                   Copier le lien