TGUI pAI Hotfix 1 (#63160)

Adds a new ui state so that players can access the paicard tgui while it's slotted in their PDA (inside the pda wasn't technically in the user's close inventory).
Adds some documentation for the pAI candidate file
Users now get notifications if they can't save files (guest keys).
pAIs previously had NO on screen indicator of hack progress, so I've given them a progressbar over the door
More visual output for pAIs
More output for edge cases
More documentation
Fixes #63161

code/game/objects/items/devices/PDA/PDA.dm

@@ -678,6 +678,7 @@ GLOBAL_LIST_EMPTY(PDAs)
 						pai.attack_self(U)
 					if("2") // Eject pAI device
 						usr.put_in_hands(pai)
+						pai.slotted = FALSE
 						to_chat(usr, span_notice("You remove the pAI from the [name]."))
 
 //SKILL FUNCTIONS===================================
@@ -1085,6 +1086,7 @@ GLOBAL_LIST_EMPTY(PDAs)
 		if(!user.transferItemToLoc(C, src))
 			return
 		pai = C
+		pai.slotted = TRUE
 		to_chat(user, span_notice("You slot \the [C] into [src]."))
 		update_appearance()
 		updateUsrDialog()

code/game/objects/items/devices/paicard.dm

@@ -11,8 +11,12 @@
 	custom_premium_price = PAYCHECK_HARD * 1.25
 	///don't spam alert messages.
 	var/alert_cooldown
+	/// If the pAIcard is slotted in a PDA
+	var/slotted = FALSE
+	/// Any pAI personalities inserted
 	var/mob/living/silicon/pai/pai
-	var/emotion_icon = "off" ///what emotion icon we have. handled in /mob/living/silicon/pai/Topic()
+	///what emotion icon we have. handled in /mob/living/silicon/pai/Topic()
+	var/emotion_icon = "off"
 	resistance_flags = FIRE_PROOF | ACID_PROOF | INDESTRUCTIBLE
 
 /obj/item/paicard/suicide_act(mob/living/user)
@@ -63,7 +67,7 @@
 		ui.open()
 
 /obj/item/paicard/ui_state(mob/user)
-	return GLOB.inventory_state
+	return GLOB.paicard_state
 
 /obj/item/paicard/ui_data(mob/user)
 	. = ..()