You can spawn in as your static when taking a ghost role (#93809)

## About The Pull Request

When take a ghost role from a ghost role sleeper, if you became a ghost
by observing you will be offered the opportunity to spawn in as your
static. Obviously if you joined the round normally or have already
spawned in as a ghost role you won't be prompted. No cloning yourself
allowed.

Not every ghost role allows this, and you won't get the prompt if your
static is a race that breathes plasma (basically just those purple
skeletons) because that opens up a giant can of worms. However, you
_will_ get the prompt if you are playing as any other race. (I'm pretty
sure every ghost role has power for ethereals besides ashwalkers but
that's not one of the ghost roles that lets you spawn as your static for
super obvious reasons)

Some ghost roles, like pirates, will allow you to spawn in as your
static but overwrite your name.

## Why It's Good For The Game

Felinid comms agent felinid comms agent felinid comms agent felinid
comms agent felinid comms agent felinid comms agent felinid comms agent
felinid comms agent felinid comms agent felinid comms agent felinid
comms agent felinid comms agent felinid comms agent felinid comms agent

## Changelog
🆑
add: You may now spawn in as your static when picking a ghost role
/🆑

---------

Co-authored-by: Fghj240 <fakeemail@notrealemail.com>

code/modules/mob_spawn/mob_spawn.dm

@@ -114,6 +114,8 @@
 	/// A list of the ckeys that currently are trying to access this spawner, so that they can't try to spawn more than once (in case there's sleeps).
 	/// Static because you only really want to be able to spawn in one spawner at a time, obviously.
 	var/static/list/ckeys_trying_to_spawn
+	///bitflag that determines if players can spawn in as their statics
+	var/allow_custom_character = NONE
 
 	////descriptions
 
@@ -206,7 +208,7 @@
  * If you are manually forcing a player into this mob spawn,
  * you should be using this and not directly calling [proc/create].
  */
-/obj/effect/mob_spawn/ghost_role/proc/create_from_ghost(mob/dead/user)
+/obj/effect/mob_spawn/ghost_role/proc/create_from_ghost(mob/dead/observer/user)
 	ASSERT(istype(user))
 	var/user_ckey = user.ckey // We need to do it before everything else, because after the create() the ckey will already have been transferred.
 
@@ -214,6 +216,15 @@
 	uses -= 1 // Remove a use before trying to spawn to prevent strangeness like the spawner trying to spawn more mobs than it should be able to
 	if(!temp_body)
 		user.mind = null // dissassociate mind, don't let it follow us to the next life
+	var/species_pref = user.client.prefs.read_preference(/datum/preference/choiced/species)
+	var/datum/species/user_species = GLOB.species_prototypes[species_pref]
+	if(user_species.inherent_respiration_type == RESPIRATION_PLASMA) // Stupid flammable skeletons...
+		user.started_as_observer = null
+	else if(user.started_as_observer && allow_custom_character)
+		var/static_prompt = "Because you haven't taken a role so far, you may spawn in as [(allow_custom_character & GHOSTROLE_ALLOW_SPECIES || user_species == /datum/species/human) ? "" : "a human version of"] your customized character with a random name. Would you like to?"
+		var/static_prompt_result = tgui_alert(user, static_prompt, "Custom Character", list("Yes", "No"), 10 SECONDS)
+		if(static_prompt_result != "Yes")
+			user.started_as_observer = null
 
 	var/created = create(user)
 	LAZYREMOVE(ckeys_trying_to_spawn, user_ckey) // We do this AFTER the create() so that we're basically sure that the user won't be in their ghost body anymore, so they can't click on the spawner again.
@@ -239,6 +250,14 @@
 /obj/effect/mob_spawn/ghost_role/special(mob/living/spawned_mob, mob/mob_possessor)
 	. = ..()
 	if(mob_possessor)
+		var/mob/dead/observer/observer_possessor = mob_possessor
+		if(observer_possessor.started_as_observer)
+			var/old_name = spawned_mob.real_name
+			if(allow_custom_character & GHOSTROLE_ALLOW_OTHER)
+				mob_possessor.client.prefs.safe_transfer_prefs_to(spawned_mob)
+				spawned_mob.fully_replace_character_name(newname = old_name)
+			if(!(allow_custom_character & GHOSTROLE_ALLOW_SPECIES || ishumanbasic(spawned_mob)))
+				spawned_mob.set_species(/datum/species/human)
 		if(mob_possessor.mind)
 			mob_possessor.mind.transfer_to(spawned_mob, force_key_move = TRUE)
 		else
@@ -247,7 +266,6 @@
 	if(spawned_mind)
 		spawned_mob.mind.set_assigned_role_with_greeting(SSjob.get_job_type(spawner_job_path))
 		spawned_mind.name = spawned_mob.real_name
-
 	if(show_flavor)
 		var/output_message = span_infoplain("<span class='big bold'>[you_are_text]</span>")
 		if(flavour_text != "")