fix: optimize state effects in assignments client

Author: AradhyaX

app/dashboard/assignments/AssignmentsClient.tsx

@@ -344,7 +344,7 @@ export function AssignmentsClient() {
       description: a.description,
       subject: a.subject,
       class: a.class,
-      deadline: a.deadline,
+      deadline: a.deadline.slice(0, 10),
       maxMarks: a.maxMarks,
     });
     setModalOpen(true);
@@ -387,14 +387,17 @@ export function AssignmentsClient() {
       ),
     );
     try {
-      await fetch(`/api/assignments/${id}`, {
+      const res = await fetch(`/api/assignments/${id}`, {
         method: "PUT",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
           kanbanStatus: col,
           status: col === "submitted" ? "closed" : "active",
         }),
       });
+      if (!res.ok) {
+        throw new Error(`HTTP ${res.status}`);
+      }
     } catch (error) {
       fetchAssignments();
       toast(