feat(ui): improve error handling on categories page

app/(tabs)/categories/mocks/page.tsx

@@ -121,11 +121,16 @@ export default function MockScreen() {
                   </button>
                 </div>
               ))
-            ) : (
+            ) : refreshing ? (
               <div className="flex flex-col items-center justify-center">
                 <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-blue-500 mb-4"></div>
                 <p className="text-xl font-medium text-center">Loading...</p>
               </div>
+            ) : (
+              <DestructibleAlert
+                text="There aren't any tests available for you. Check back later?"
+                variant="warning"
+              />
             )}
           </div>
           <div className="flex justify-center mt-4">