Another Observer Hard Del Fix (#22284)

Another and hopefully my last fix for the Observer hard dels. This
probably but might not also clear the Storyteller harddel since they're
an observer child. But I dunno. I have actually tested this.

<img width="670" height="435" alt="image"
src="https://github.com/user-attachments/assets/41e75448-211d-429b-b694-43b9d025e996"
/>

code/modules/mob/abstract/ghost/observer/observer.dm

@@ -85,7 +85,12 @@
 	real_name = name
 
 /mob/abstract/ghost/observer/Destroy()
+	if(client)
+		for(var/image/I in client.images)
+			if(I.loc == src)
+				qdel(I)
 	QDEL_NULL(hud)
+	mind = null
 	return ..()
 
 /mob/abstract/ghost/observer/proc/initialise_postkey(set_timers = TRUE)