Re-attempt at vv editing lobby music (#96093)

## About The Pull Request

Previous attempt was in
https://github.com/tgstation/tgstation/pull/95870 but I got 0 feedback
and it just staled and closed.
Instead of adding it as a secret button I am simply making it so vv
editing the ticker's lobby music will properly update it for everyone.

## Why It's Good For The Game

QoL for admins.

## Changelog

🆑
admin: Changing lobby music now updates for people in the lobby.
/🆑

code/controllers/subsystem/ticker.dm

@@ -203,6 +203,11 @@ SUBSYSTEM_DEF(ticker)
 				else
 					reboot_hud.maptext = MAPTEXT_PIXELLARI("<center>Server rebooting in:\n\ [DisplayTimeText(timeleft(SSticker.reboot_timer), 1)]</center>")
 
+/datum/controller/subsystem/ticker/vv_edit_var(var_name, var_value)
+	if(var_name == NAMEOF(src, login_music))
+		set_lobby_music(var_value, override = TRUE)
+	return ..()
+
 /// Checks if the round should be ending, called every ticker tick
 /datum/controller/subsystem/ticker/proc/check_finished()
 	if(!setup_done)
@@ -887,6 +892,10 @@ SUBSYSTEM_DEF(ticker)
 		return
 
 	login_music = new_music
+	//we just overrode the song, let's update everyone.
+	if(override)
+		for(var/mob/dead/new_player/new_player as anything in GLOB.new_player_list)
+			new_player?.client.playtitlemusic()
 
 #undef ROUND_START_MUSIC_LIST
 #undef SS_TICKER_TRAIT