feat(nav): add GameState.set_current_room and AudioManager.DEFAULT_MUSIC_VOLUME

scripts/autoload/AudioManager.gd

@@ -3,6 +3,7 @@
 extends Node
 
 const CROSSFADE_DURATION: float = 0.8
+const DEFAULT_MUSIC_VOLUME: float = 0.6
 
 const _MUSIC_MAP: Dictionary = {
 	0: "res://assets/audio/music/floor_0.ogg",

scripts/autoload/GameState.gd

@@ -73,6 +73,11 @@ func clear_chest_state(chest_id: String) -> void:
 	state_changed.emit()
 
 
+func set_current_room(room: String) -> void:
+	current_room = room
+	state_changed.emit()
+
+
 func get_save_data() -> Dictionary:
 	var positions: Dictionary = {}
 	for key: String in _character_positions:

test/unit/test_audio_manager.gd

@@ -69,3 +69,7 @@ func test_music_map_has_all_four_floors() -> void:
 	assert_true(AudioManager._MUSIC_MAP.has(1))
 	assert_true(AudioManager._MUSIC_MAP.has(2))
 	assert_true(AudioManager._MUSIC_MAP.has(3))
+
+
+func test_default_music_volume_constant_is_0_6() -> void:
+	assert_eq(AudioManager.DEFAULT_MUSIC_VOLUME, 0.6)

test/unit/test_game_state.gd

@@ -181,3 +181,16 @@ func test_apply_save_data_restores_chest_state() -> void:
 	}
 	GameState.apply_save_data(data)
 	assert_eq(GameState.get_chest_state("reception_desk_test"), ["clipboard", "pen"])
+
+
+func test_set_current_room_updates_value() -> void:
+	GameState.set_current_room("xray")
+	assert_eq(GameState.current_room, "xray")
+	GameState.set_current_room("reception")
+
+
+func test_set_current_room_emits_state_changed() -> void:
+	watch_signals(GameState)
+	GameState.set_current_room("pharmacy")
+	assert_signal_emitted(GameState, "state_changed")
+	GameState.set_current_room("reception")