Fix random names breaking preferences (#62668)

The randomization (specifically from the random names secret) overrode your preferences, this fixes that.

code/modules/unit_tests/_unit_tests.dm

@@ -45,6 +45,7 @@
 
 #include "achievements.dm"
 #include "anchored_mobs.dm"
+#include "anonymous_themes.dm"
 #include "bespoke_id.dm"
 #include "binary_insert.dm"
 #include "bloody_footprints.dm"

code/modules/unit_tests/anonymous_themes.dm

@@ -0,0 +1,23 @@
+/// Ensure that anonymous themes works without changing your preferences
+/datum/unit_test/anonymous_themes
+
+/datum/unit_test/anonymous_themes/Run()
+	GLOB.current_anonymous_theme = new /datum/anonymous_theme
+
+	var/mob/living/carbon/human/human = allocate(/mob/living/carbon/human)
+
+	var/datum/client_interface/client = new
+	human.mock_client = client
+
+	client.prefs = new
+
+	client.prefs.write_preference(GLOB.preference_entries[/datum/preference/name/real_name], "Prefs Biddle")
+
+	human.apply_prefs_job(client, SSjob.GetJobType(/datum/job/assistant))
+
+	TEST_ASSERT_NOTEQUAL(human.real_name, "Prefs Biddle", "apply_prefs_job didn't randomize human name with an anonymous theme")
+	TEST_ASSERT_EQUAL(client.prefs.read_preference(/datum/preference/name/real_name), "Prefs Biddle", "Anonymous theme overrode original prefs")
+
+/datum/unit_test/anonymous_themes/Destroy()
+	QDEL_NULL(GLOB.current_anonymous_theme)
+	return ..()