Removes buy limit on traitor discounts (#91969)

## About The Pull Request

Removes the buy limit on items in traitor uplink discount tab.

Purchase limits are kept on a few problematic items
A purchase limit was added to powersink

## Why It's Good For The Game

Traitor is a great role for doing interesting things. I'm loving the
removal of progtot as it has encouraged players to think of interesting
things to do instead of purely game. I want to further encourage
interesting things by removing the buy limit on the discounts for
traitor uplink.
Unfortunately this does add a bit of power to traitors through certain
discounts like syndicate bomb, but it doesn't add too much. Apart from a
few niche items, what is a traitor going to do with 7 syndicate modsuits
or 4 revolvers? One purchase generally gives them enough power to
succeed.
I'm hoping this encourages more traitors to team up or do something
funny with 20 e-daggers.

also enables general griefsky

## Changelog

🆑
balance: Removes buy limit on traitor discounts
balance: Purchase limit was added to powersink
/🆑

code/modules/uplink/uplink_items.dm

@@ -29,7 +29,17 @@
 			"Use only as directed.",
 			"16% sales tax will be charged for orders originating within Space Nebraska.",
 		)
-		uplink_item.limited_stock = limited_stock
+
+		//We want to limit the purchase amount of some items without adjusting the pricing.
+		if (uplink_item.limited_discount_stock > 0) {
+			uplink_item.limited_stock = uplink_item.limited_discount_stock
+		}
+
+		//if stock limited is passed into the function, we'll override everything
+		if (limited_stock > 0) {
+			uplink_item.limited_stock = limited_stock
+		}
+
 		if(uplink_item.cost >= 20) //Tough love for nuke ops
 			discount *= 0.5
 		uplink_item.stock_key = WEAKREF(uplink_item)
@@ -73,6 +83,8 @@
 	var/stock_key = UPLINK_SHARED_STOCK_UNIQUE
 	/// How many items of this stock can be purchased.
 	var/limited_stock = -1 //Setting this above zero limits how many times this item can be bought by the same traitor in a round, -1 is unlimited
+	/// How many items of this stock can be purchased from the discount tab.
+	var/limited_discount_stock = -1
 	/// A bitfield to represent what uplinks can purchase this item.
 	/// See [`code/__DEFINES/uplink.dm`].
 	var/purchasable_from = ALL

code/modules/uplink/uplink_items/device_tools.dm

@@ -269,6 +269,7 @@
 	progression_minimum = 20 MINUTES
 	item = /obj/item/powersink
 	cost = 11
+	limited_stock = 1
 
 /datum/uplink_item/device_tools/syndicate_contacts
 	name = "Polarized Contact Lenses"

code/modules/uplink/uplink_items/explosive.dm

@@ -86,6 +86,7 @@
 	desc = "A variation of the syndicate bomb designed to produce a large EMP effect."
 	item = /obj/item/sbeacondrop/emp
 	cost = 7
+	limited_discount_stock = 4
 
 /datum/uplink_item/explosives/syndicate_bomb/emp/New()
 	..()
@@ -103,6 +104,7 @@
 	progression_minimum = 30 MINUTES
 	item = /obj/item/sbeacondrop/bomb
 	cost = 11
+	limited_discount_stock = 4
 
 /datum/uplink_item/explosives/syndicate_bomb/New()
 	. = ..()