fixed a bit

app/(auth)/register/page.js

@@ -23,6 +23,13 @@ export default function Register() {
         body: JSON.stringify({ username, password }),
       });
 
+      if (!response.ok) {
+        const result = await response.json();
+        setError(result.error || "Failed to register");
+        setIsLoading(false);
+        return;
+      }
+
       const result = await response.json();
 
       if (result.error) {
@@ -44,7 +51,11 @@ export default function Register() {
         }
       }
     } catch (err) {
-      setError("An unexpected error occurred");
+      if (err instanceof SyntaxError) {
+        setError("Unexpected response from server");
+      } else {
+        setError("An unexpected error occurred");
+      }
       console.error(err);
       setIsLoading(false);
     }