[FE-COMP-003] fix: Fix TypeScript errors in empty states

- Fixed isOwnProfile reference in UserProfilePage
- Fixed possibly undefined data in PlaylistList pagination

apps/web/src/features/playlists/components/PlaylistList.tsx

@@ -353,7 +353,7 @@ export function PlaylistList({
             className="text-xs sm:text-sm text-muted-foreground text-center sm:text-left"
             aria-live="polite"
           >
-            Page {currentPage} sur {totalPages} ({data.total} playlists)
+            Page {currentPage} sur {totalPages} ({data?.total || 0} playlists)
           </div>
           <div className="flex items-center gap-2 w-full sm:w-auto">
             <Button

apps/web/src/features/profile/pages/UserProfilePage.tsx

@@ -256,7 +256,7 @@ export function UserProfilePage() {
                     <Music className="h-12 w-12 mx-auto mb-4 text-muted-foreground opacity-50" />
                     <h3 className="text-lg font-semibold mb-2">No tracks yet</h3>
                     <p className="text-muted-foreground">
-                      {isOwnProfile
+                      {currentUser?.id === profile.id
                         ? 'Start by uploading your first track to share with others.'
                         : 'This user has not uploaded any tracks yet.'}
                     </p>
@@ -298,7 +298,7 @@ export function UserProfilePage() {
                     <Library className="h-12 w-12 mx-auto mb-4 text-muted-foreground opacity-50" />
                     <h3 className="text-lg font-semibold mb-2">No playlists yet</h3>
                     <p className="text-muted-foreground">
-                      {isOwnProfile
+                      {currentUser?.id === profile.id
                         ? 'Create your first playlist to organize your favorite tracks.'
                         : 'This user has not created any playlists yet.'}
                     </p>