Refactor priority-change path in mo_task_priority()

Previously, mo_task_priority() only updated the task’s time slice and
priority level. With the new scheduler design, tasks are kept in
per-priority ready queues, so mo_task_priority() must also handle
migrating tasks between these queues.

This change supports task migration from original ready queue to the new
priority ready queue.

Author: vicLin8712

kernel/task.c

@@ -996,12 +996,30 @@ int32_t mo_task_priority(uint16_t id, uint16_t priority)
         return ERR_TASK_NOT_FOUND;
     }
 
+    bool is_current = (kcb->task_current->data == task);
+
+    /* Removed task from ready queue */
+    if (task->state == TASK_RUNNING || task->state == TASK_READY) {
+        sched_dequeue_task(task);
+
+        /* Update new properties */
+        task->prio = priority;
+        task->prio_level = extract_priority_level(priority);
+
+        /* Enqueue task node into  new priority ready queue*/
+        sched_enqueue_task(task);
+    }
+
     /* Update priority and level */
     task->prio = priority;
     task->prio_level = extract_priority_level(priority);
     task->time_slice = get_priority_timeslice(task->prio_level);
 
     CRITICAL_LEAVE();
+
+    if (is_current)
+        mo_task_yield();
+
     return ERR_OK;
 }