[MIRROR] Adds an achievement for saving a cascading SM from the final countdown. [MDB IGNORE] (#23358)

* Adds an achievement for saving a cascading SM from the final countdown. (#77900)

## About The Pull Request

Adds the "All Within Theoretical Limits" achievement. You get the
achievement for standing inside the engine room at the time where the SM
crystal heals from 0% health (when the crystal says "Crystalline
hyperstructure returning to safe operating parameters. Harmonic
frequency restored within emergency bounds. Anti-resonance filter
initiated"), and waiting until the SM heals to at least 25% health.

## Why It's Good For The Game

This rewards engineers who stay behind and try to save the engine even
in the most dire circumstances.

## Changelog
🆑 distributivgesetz
add: Add an achievement for saving a cascading engine from the final
countdown.
/🆑

* Adds an achievement for saving a cascading SM from the final countdown.

---------

Co-authored-by: distributivgesetz <distributivgesetz93@gmail.com>

code/__DEFINES/achievements.dm

@@ -54,6 +54,7 @@
 #define MEDAL_EARTHQUAKE_VICTIM "Earthquake Victim"
 #define MEDAL_DEBT_EXTINGUISHED "Debt Extinguished"
 #define MEDAL_ARCHMAGE "Archmage"
+#define MEDAL_THEORETICAL_LIMITS "All Within Theoretical Limits"
 
 //Skill medal hub IDs
 #define MEDAL_LEGENDARY_MINER "Legendary Miner"

code/datums/achievements/misc_achievements.dm

@@ -241,3 +241,9 @@
 	desc = "I've paid my dues, shift after shift... I've done my sentence but commited no griff..."
 	database_id = MEDAL_DEBT_EXTINGUISHED
 	icon = "outdebted"
+
+/datum/award/achievement/misc/theoretical_limits
+	name = "All Within Theoretical Limits"
+	desc = "I never thought I'd see a resonance cascade, let alone prevent one..."
+	database_id = MEDAL_THEORETICAL_LIMITS
+	icon = "theoreticallimits"

code/modules/power/supermatter/supermatter.dm

@@ -169,6 +169,9 @@ GLOBAL_DATUM(main_supermatter_engine, /obj/machinery/power/supermatter_crystal)
 	/// Only values greater or equal to the current one can change the strat.
 	var/delam_priority = SM_DELAM_PRIO_NONE
 
+	/// Lazy list of the crazy engineers who managed to turn a cascading engine around.
+	var/list/datum/weakref/saviors = null
+
 /obj/machinery/power/supermatter_crystal/Initialize(mapload)
 	. = ..()
 	gas_percentage = list()
@@ -312,6 +315,16 @@ GLOBAL_DATUM(main_supermatter_engine, /obj/machinery/power/supermatter_crystal)
 	processing_sound()
 	handle_high_power()
 	psychological_examination()
+
+	// handle the engineers that saved the engine from cascading, if there were any
+	if(get_status() < SUPERMATTER_EMERGENCY && !isnull(saviors))
+		for(var/datum/weakref/savior_ref as anything in saviors)
+			var/mob/living/savior = savior_ref.resolve()
+			if(!istype(savior)) // didn't live to tell the tale, sadly.
+				continue
+			savior.client?.give_award(/datum/award/achievement/misc/theoretical_limits, savior)
+		LAZYNULL(saviors)
+
 	if(prob(15))
 		supermatter_pull(loc, min(internal_energy/850, 3))//850, 1700, 2550
 	update_appearance()
@@ -515,6 +528,17 @@ GLOBAL_DATUM(main_supermatter_engine, /obj/machinery/power/supermatter_crystal)
 
 		if(healed)
 			final_countdown = FALSE
+
+			if(!istype(delamination_strategy, /datum/sm_delam/cascade))
+				return
+
+			for(var/mob/living/lucky_engi as anything in mobs_in_area_type(list(/area/station/engineering/supermatter)))
+				if(isnull(lucky_engi.client))
+					continue
+				if(isanimal_or_basicmob(lucky_engi))
+					continue
+				LAZYADD(saviors, WEAKREF(lucky_engi))
+
 			return // delam averted
 		sleep(1 SECONDS)