Backend changes

backend/model/submission.go

@@ -1,10 +1,15 @@
 package model
 
+import "time"
+
 // CodeSubmission represents a code submission for execution
 type CodeSubmission struct {
-	ID       string `json:"id"`
-	Code     string `json:"code"`
-	Language string `json:"language"` // Added language field
-	Status   string `json:"status"`
-	Output   string `json:"output"`
+	ID          string    `json:"id"`
+	Code        string    `json:"code"`
+	Language    string    `json:"language"`
+	Status      string    `json:"status"` // "queued", "running", "completed", "failed"
+	QueuedAt    time.Time `json:"queuedAt"`
+	StartedAt   time.Time `json:"startedAt,omitempty"`
+	CompletedAt time.Time `json:"completedAt,omitempty"`
+	Output      string    `json:"output"`
 }