Refactor enqueuing logic for the new scheduler

This commit refactors mo_enqueue_task() to support the data structures
for the new scheduler.

The RR cursor must be advanced if it same as the running task, which
only happens in one task in ready queue. RR cursor will point to new
enqueued task for scheduler consistency.

Author: vicLin8712

kernel/task.c

@@ -86,7 +86,7 @@ static const uint8_t priority_timeslices[TASK_PRIORITY_LEVELS] = {
     TASK_TIMESLICE_IDLE      /* Priority 7: Idle */
 };
 
-/* Mark task as ready (state-based) */
+/* Enqueue task into ready queue */
 static void sched_enqueue_task(tcb_t *task);
 
 /* Utility and Validation Functions */
@@ -369,17 +369,39 @@ void _yield(void) __attribute__((weak, alias("yield")));
  * practical performance with strong guarantees for fairness and reliability.
  */
 
-/* Add task to ready state - simple state-based approach */
+/* Enqueue task into ready queue */
 static void sched_enqueue_task(tcb_t *task)
 {
     if (unlikely(!task))
         return;
 
+    uint8_t prio_level = task->prio_level;
+
     /* Ensure task has appropriate time slice for its priority */
-    task->time_slice = get_priority_timeslice(task->prio_level);
+    task->time_slice = get_priority_timeslice(prio_level);
     task->state = TASK_READY;
 
-    /* Task selection is handled directly through the master task list */
+    list_t **rq = &kcb->ready_queues[prio_level];
+    list_node_t **cursor = &kcb->rr_cursors[prio_level];
+
+    if (!*rq)
+        *rq = list_create();
+
+    list_pushback_node(*rq, &task->rq_node);
+
+    /* Update task count in ready queue */
+    kcb->queue_counts[prio_level]++;
+
+    /* Setup first rr_cursor */
+    if (!*cursor)
+        *cursor = &task->rq_node;
+
+    /* Advance cursor when cursor same as running task */
+    if (*cursor == kcb->task_current)
+        *cursor = &task->rq_node;
+
+    bitmap_set(task->prio_level);
+    return;
 }
 
 /* Remove task from ready queues - state-based approach for compatibility */