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 commit adds dequeue/enqueue logic for tasks in TASK_RUNNING or
TASK_READY state, as such tasks must reside in a ready queue and a
priority change implies ready-queue migration.

The priority fields are still updated as part of the migration path:
sched_dequeue_task() relies on the current priority, while the enqueue
operation needs the new priority. Therefore, the priority update is
performed between the dequeue and enqueue steps.

If the priority change happens while the task is running, it must yield
immediately to preserve the scheduler’s strict task-ordering policy.

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;
 }