feat(cogs): add get_critical_tasks method to Afk for dynamic task registration

- Add get_critical_tasks method to register handle_afk_expiration task
- Import CriticalTaskConfig and TaskPriority from task_manager
- Enable automatic task registration and monitoring for AFK expiration
- Follow new cog-driven task management pattern for utility tasks

Author: kzndotsh

tux/cogs/utility/afk.py

@@ -12,6 +12,7 @@
 from tux.cogs.utility import add_afk, del_afk
 from tux.database.controllers import DatabaseController
 from tux.utils.functions import generate_usage
+from tux.utils.task_manager import CriticalTaskConfig, TaskPriority
 
 # TODO: add `afk until` command, or add support for providing a timeframe in the regular `afk` and `permafk` commands
 
@@ -220,6 +221,16 @@ async def _get_expired_afk_entries(self, guild_id: int) -> list[AFKModel]:
 
         return [entry for entry in entries if entry.until is not None and entry.until < current_time]
 
+    def get_critical_tasks(self) -> list[CriticalTaskConfig]:
+        """Get critical tasks for this cog.
+
+        Returns
+        -------
+        list[CriticalTaskConfig]
+            List of critical task configurations
+        """
+        return [CriticalTaskConfig("afk_expiration_handler", "Afk", "handle_afk_expiration", TaskPriority.NORMAL)]
+
 
 async def setup(bot: Tux) -> None:
     await bot.add_cog(Afk(bot))