Adds the E-2 Earthcracker, a traitor tool for premeditated sabotage. (#95731)

## About The Pull Request

Adds a new traitor item, the E-2 Earthcracker. The Earthcracker is a
handheld sabotage device that you can deploy onto the ground in order to
deliberately create a weakpoint on that location.

As a recap, weakpoints can be exploited with a sufficiently large enough
explosive in order to create a chain of cracked turfs from it's
location, randomly breaking floors and walls, as well as attempting to
create new weakpoints that will allow for more of the hull to break
down. Weakpoints, if discovered, can be welded to taped up to repair
them using sticky tape.

The earthcracker creates a longer, and larger weakpoint than the kind
that spawn naturally. However, to use this subtly, you'll need to hide
the weakpoint created, as well as clear away the spent earthcracker by
using a wrench.

Practical use is: Get the earthcracker, use in hand to arm/anchor onto a
turf (Can be unwrenched at this point), activate with an empty hand to
begin the cracking process, then wrench away, and you have a well
hidden, high power sabotage device.

Two variants are available in-game: The E-2 Earthcracker which can be
obtained from the traitor uplink at 2TC each, and the E-1 Earthcracker
which can be purchased on the black market. The E-1 variant spawns
normal run-of-the-mill weakpoints as opposed to the E-2, with a 30%
availability from the back market, at a cost of 200-600 credits.


![earthcraking](https://github.com/user-attachments/assets/0ab3a5af-f6c3-4096-b59a-7a1b44a01700)


## Why It's Good For The Game

I'll be frank, I don't think we necessarily need *more* tools to cause
havoc, but I wanted to expand the weakpoint framework a bit and this
idea came to mind. The Earthcracker fits in the same category as C4, but
without a signifigant amount of the control that comes from C4 and
absolutely from X4. This stands to cause more damage across the hull,
with the ability to keep expanding the crack. For that reason, I think I
may have underpriced this in terms of TC, but I'm up for discussion on
if it needs to go up to a 3-5 range.

In an ideal world, this could be used for making booby traps, such as
planting an earthcracker in an area like escape or a larger department,
and then triggering the weakpoint when the right people are around, even
through something like a detomatrix or a trigger on a grenade.

As an added reminder, weakpoints have a dedicated method to repair them
if discovered, that being welding them or hitting them with sticky tape
to repair them quickly, offering some counterplay.

I also added a lighter variant onto the black market as a fun, dubious
thing to have on the black market.

## Changelog
🆑
add: Adds the E-2 Earthcracker device as a purchasable traitor item for
2 TC. Use it to create potentially devastating weakpoints onto the
station!
/🆑

code/modules/cargo/markets/market_items/weapons.dm

@@ -153,3 +153,13 @@
 	price_max = CARGO_CRATE_VALUE * 5
 	stock_max = 2
 	availability_prob = 80
+
+/datum/market_item/weapon/earthcracker
+	name = "E-1 Earthcracker"
+	desc = "Surplus mining equipment from one of the many, nameless asteroid mining companies bought out by Nanotrasen in this sector.\
+		While they were decent enough at mining asteroids, these things really shine at leaving large cracks on station-class hulls when deployed these days."
+	item = /obj/item/earthcracker/small
+	price_min = CARGO_CRATE_VALUE
+	price_max = CARGO_CRATE_VALUE * 3
+	stock_max = 1
+	availability_prob = 30

code/modules/uplink/uplink_items/explosive.dm

@@ -121,6 +121,15 @@
 	purchasable_from = ~UPLINK_ALL_SYNDIE_OPS /// Ops get their own version.
 	limited_discount_stock = 4
 
+/datum/uplink_item/explosives/earthcracker
+	name = "E-2 Earthcracker"
+	desc = "The E-2 Earthcracker makes for a great partner to any conventional explosive. Set the device up on any station hull, arm, and activate.\
+		What remains is a conventionally dangerous weakpoint, that will crack open a random pattern of floors upon being hit with an explosive force.\
+		That pattern of cracks will in-turn also create additional cracks, ad-finimum if not repaired. It can also be used for mining out rock, though that's less advised."
+	item = /obj/item/earthcracker
+	cost = 2
+	limited_discount_stock = 2
+
 /datum/uplink_item/explosives/syndicate_bomb/New()
 	. = ..()
 	desc = replacetext(desc, "%MIN_BOMB_TIMER", SYNDIEBOMB_MIN_TIMER_SECONDS)