Big gun go boom: The Coilgun rework + Sol Frigate tweaks (#21604)

![halo-mac](https://github.com/user-attachments/assets/b3a508e2-0627-4758-bcd2-483f9ed6abea)
Reworks the long-neglected Solarian Coilgun into a practical weapon
that's able to be used by offships, not just for events. Test firing
images below.

This PR also replaces the Sol Frigate's Longbow with the brand new
Coilgun, plus several other fixes to issues that were found during
playtesting.

### TEST FIRINGS
<img width="901" height="1023" alt="Screenshot 2025-11-16 201802"
src="https://github.com/user-attachments/assets/a9e2ef93-9cfb-4602-a258-09046c2914a5"
/>
<img width="1077" height="787" alt="Screenshot 2025-11-16 201749"
src="https://github.com/user-attachments/assets/6f588756-dd5d-47b1-b768-a43d28a438db"
/>
_Two coilgun rounds fired at the Aft of the Horizon, deck three._ 


<img width="1008" height="1012" alt="Screenshot 2025-11-16 053206"
src="https://github.com/user-attachments/assets/df44580b-7d73-4424-951e-7fd5bdcfe71b"
/>
<img width="957" height="990" alt="Screenshot 2025-11-16 053214"
src="https://github.com/user-attachments/assets/b9aa6ac9-bf36-4e7d-a94c-a7b1198c3a62"
/>
_For comparison, a full 5-round Salvo of AP-HE flak fired from the Sol
Frigate's Grauwolf at the Horizon's longbow. Note how some targets
missed the mark entirely and hit the HR and the Captain's office._

code/modules/overmap/ship_weaponry/weaponry/coilgun.dm

@@ -1,7 +1,7 @@
 /obj/machinery/ship_weapon/coilgun
-	name = "type 21 nadziak solarian coilgun"
-	desc = "The venerable Nadziak-class line of coilguns was born in the fires of the Interstellar War, where its ability to shred shields and low-class hulls have ensured its immortality in the infrastructure of the Solarian Navy."
-	desc_extended = "Although originally an expensive blunder made by over-worked Kumar Arms designers, the Nadziak later preformed to an outstanding degree following numerous improvements. Its fame among post-War Admirals was such that its name and purpose has largely remained the same, with a new 'Type' iteration commissioned every decade or so. With the expulsion of Zavodskoi and its subsidiary from Solarian space, this aging giant and symbol of military might is under threat of being consumed by the resulting arms manufacturing vacuum."
+	name = "M55A2 Coilgun"
+	desc = "A venerable mainstay of the Solarian Navy's arsenal and the prime reason of why Issac Newton is still the deadliest human in the Spur. The M55A2 is capable of firing rifled tungsten rods the size of flagpoles at supersonic speeds. Despite it's lackluster performance against a well-armored ship of the line, it's ability to seriously damage any smaller vessel with a few well-aimed shots has earned the platform's ubiqutous status in the Alliance's 100 fleets."
+	desc_extended = "Originally desgined just before the outbreak of the Interstellar War, the M55 series of Intermediate Coilgun have seen extensive service from the battles over Gadpathur and Xanu to the actions of the First invasion of Tau Ceti with the M55A1. However, in spite of the A1 variant's significant advancements in percision and ease of use, the M55's greatest hour was arguably in the discord and chaos of the Solarian Civil War. With the faster-firing and much easier to produce M55A2 being used by all sides of the conflict. Tried and tested on the warlord-infested ruins of Southern Sol and over the smoldering battlefields of San Colette, the M55A2 still remains the 'workhorse gun' of the Solarian Navy to this day. It is mostly used as a primary armament (either on turret mounts or fixed in fore-facing casemates) aboard escort vessels. And on secondary turret mounts aboard a ship of the line. "
 	icon = 'icons/obj/machinery/ship_guns/sol_coilgun.dmi'
 	icon_state = "weapon_base"
 	projectile_type = /obj/projectile/ship_ammo/coilgun
@@ -14,19 +14,19 @@
 /obj/item/ship_ammunition/coilgun
 	name = "tungsten rod pack"
 	name_override = "tungsten rod"
-	desc = "A pack of rods used as ammunition for a coilgun."
+	desc = "A pack of rods used as ammunition for the M55A2 intermediate coilgun, if the obvious labelling and handling insturctions didn't already give it away."
 	icon = 'icons/obj/ammo.dmi'
 	icon_state = "trodpack-2"
 	caliber = SHIP_CALIBER_COILGUN
 	overmap_icon_state = "cannon"
-	impact_type = SHIP_AMMO_IMPACT_HE
+	impact_type = SHIP_AMMO_IMPACT_BUNKERBUSTER
 
 /obj/projectile/ship_ammo/coilgun
 	name = "high-power tungsten rod"
 	icon_state = "heavy"
 	damage = 10000
 	armor_penetration = 1000
-	penetrating = 1
+	penetrating = 50
 
 /obj/projectile/ship_ammo/coilgun/on_hit(atom/target, blocked, def_zone, is_landmark_hit)
 	. = ..()
@@ -34,7 +34,7 @@
 		var/mob/M = target
 		M.visible_message(SPAN_DANGER("<font size=5>\The [src] blows [M]'s chest apart and punches straight through!</font>"))
 	if(isturf(target) || isobj(target))
-		explosion(target, 6, 8, 10)
+		explosion(target, 1, 5, 3)
 
 /obj/machinery/ammunition_loader/sol
 	icon_state = "ammo_loader_sol"