Persistent data saves at round end instead of server restart (#21199)

* sm counter go up

* AA review

* aa review 2

code/controllers/subsystem/SSticker.dm

@@ -596,6 +596,9 @@ SUBSYSTEM_DEF(ticker)
 	//Ask the event manager to print round end information
 	SSevents.RoundEnd()
 
+	// Save the data before end of the round griefing
+	SSpersistent_data.save()
+
 	//make big obvious note in game logs that round ended
 	log_game("///////////////////////////////////////////////////////")
 	log_game("///////////////////// ROUND ENDED /////////////////////")

code/controllers/subsystem/non_firing/SSpersistent_data.dm

@@ -13,6 +13,8 @@ SUBSYSTEM_DEF(persistent_data)
 	flags = SS_NO_FIRE
 	/// List of atoms registered into the subsystem for persistent data storage. Can be anything at all
 	var/list/registered_atoms = list()
+	/// Set to true after a the end of the round to prevent griefing being saved
+	var/data_saved = FALSE
 
 /datum/controller/subsystem/persistent_data/Initialize()
 	// Load all the data of registered atoms
@@ -20,6 +22,14 @@ SUBSYSTEM_DEF(persistent_data)
 		A.persistent_load()
 
 /datum/controller/subsystem/persistent_data/Shutdown()
+	save()
+
+/datum/controller/subsystem/persistent_data/proc/save()
+	// Stops data from being saved twice
+	if(data_saved)
+		return
+	data_saved = TRUE
+
 	// Save all the data of registered atoms
 	for(var/atom/A in registered_atoms)
 		A.persistent_save()