Fix cable coil dupe and APC icon oddity (#27921)

* Fix APCs creating terminal on cut cable connection

* Fix missing icon state for empty APCs

* Make the wire panel inaccesable for empty APCs

* Make the ui inaccessable for empty APCs

* Redo this a different way so it performs correctly

* Update apc.dm

code/modules/power/apc.dm

@@ -99,8 +99,6 @@
 /obj/machinery/power/apc/connect_to_network()
 	//Override because the APC does not directly connect to the network; it goes through a terminal.
 	//The terminal is what the power computer looks for anyway.
-	if(!terminal)
-		make_terminal()
 	if(terminal)
 		terminal.connect_to_network()
 
@@ -241,6 +239,8 @@
 			icon_state = "apcemag"
 		else if(update_state & UPSTATE_WIREEXP)
 			icon_state = "apcewires"
+		else if(update_state & UPSTATE_MAINT)
+			icon_state = "apc0"
 
 	if(!(update_state & UPSTATE_ALLGOOD))
 		cut_overlays()
@@ -448,6 +448,8 @@
 				update_icon()
 		else if(emagged)
 			to_chat(user, "<span class='warning'>The interface is broken!</span>")
+		else if((stat & MAINT) && !opened)
+			..() //its an empty closed frame... theres no wires to expose!
 		else
 			panel_open = !panel_open
 			to_chat(user, "The wires have been [panel_open ? "exposed" : "unexposed"]")
@@ -630,6 +632,8 @@
 			charging = 0
 			src.update_icon()
 		return
+	if((stat & MAINT) && !opened) //no board; no interface
+		return
 	..()
 
 /obj/machinery/power/apc/ui_interact(mob/user, ui_key = "main", datum/tgui/ui = null, force_open = 0, \