fix(animations_task): improve task cleanup and prevent deadlock during stop

Author: Darcko123

firmware/main/modules/animations_task/animations_task.c

@@ -18,6 +18,8 @@ static void animations_task(void* pvParameters) {
     }
     vTaskDelay(pdMS_TO_TICKS(delay_ms));
   }
+  // Clear handle before self-delete so animations_task_stop() knows we exited.
+  animations_task_handle = NULL;
   vTaskDelete(NULL);
 }
 
@@ -36,6 +38,19 @@ void animations_task_run(void* animation_cb,
 void animations_task_stop() {
   animations_task_cb = NULL;
   running = false;
+  if (animations_task_handle == NULL) {
+    return;
+  }
+  // Wait for the task to finish its current OLED/I2C frame and exit naturally.
+  // Force-killing with vTaskDelete() while the task holds oled_mutex causes a
+  // permanent deadlock: the mutex is never released, blocking every subsequent
+  // OLED call (including sniffer_task's display update), which in turn blocks
+  // sniffer_stop()'s sem_task_over wait — resulting in a full system freeze.
+  uint8_t retries = 30;  // 30 × 10 ms = 300 ms max
+  while (animations_task_handle != NULL && retries-- > 0) {
+    vTaskDelay(pdMS_TO_TICKS(10));
+  }
+  // Safety net: if the task is still alive after 300 ms, force-delete.
   if (animations_task_handle != NULL) {
     vTaskDelete(animations_task_handle);
     animations_task_handle = NULL;