Add repo to task labels for build filtering

Add generated labels after user-defined labels to prevent tampering

server/hook.go

@@ -322,10 +322,11 @@ func PostHook(c *gin.Context) {
 		task := new(queue.Task)
 		task.ID = fmt.Sprint(item.Proc.ID)
 		task.Labels = map[string]string{}
-		task.Labels["platform"] = item.Platform
 		for k, v := range item.Labels {
 			task.Labels[k] = v
 		}
+		task.Labels["platform"] = item.Platform
+		task.Labels["repo"] = b.Repo.FullName
 
 		task.Data, _ = json.Marshal(rpc.Pipeline{
 			ID:      fmt.Sprint(item.Proc.ID),