add prewarm chunk generation

core/biome_generator/biome_generator.gd

@@ -212,6 +212,17 @@ func _physics_process(_delta: float) -> void:
 		last_pos_train = current_pos
 		_refresh_world(current_pos)
 
+func generate_initial_world_now() -> void:
+	if rail_path == null or rail_path.train_instance == null:
+		return
+
+	var train_pos = rail_path.train_instance.global_position
+	var current_pos = Vector2i(roundi(train_pos.x / chunk_size), roundi(train_pos.z / chunk_size))
+	last_pos_train = current_pos
+	_rebuild_generation_queue(current_pos)
+	_drain_generation_queue_now()
+	_drain_wire_queue_now()
+
 func collect_all_chunkinfo(root: Node, list: Array[Node]) -> void:
 	if root == null: return
 	
@@ -535,6 +546,20 @@ func _drain_generation_queue() -> void:
 		pending_generation_cells.clear()
 		pending_generation_cursor = 0
 
+func _drain_generation_queue_now() -> void:
+	while pending_generation_cursor < pending_generation_cells.size():
+		var grid_pos: Vector2i = pending_generation_cells[pending_generation_cursor]
+		pending_generation_cursor += 1
+		if board.has(grid_pos):
+			continue
+
+		var is_obstacle = _register_cell_with_ray(grid_pos)
+		if not is_obstacle:
+			_add_compatible_biome(grid_pos)
+
+	pending_generation_cells.clear()
+	pending_generation_cursor = 0
+
 func _drain_cleanup_queue() -> void:
 	var processed: int = 0
 	var start_usec: int = Time.get_ticks_usec()
@@ -595,6 +620,22 @@ func _drain_wire_queue() -> void:
 		pending_wire_cells.clear()
 		pending_wire_cursor = 0
 
+func _drain_wire_queue_now() -> void:
+	while pending_wire_cursor < pending_wire_cells.size():
+		var grid_pos: Vector2i = pending_wire_cells[pending_wire_cursor]
+		pending_wire_cursor += 1
+		pending_wire_lookup.erase(grid_pos)
+
+		if not board.has(grid_pos):
+			continue
+		if not board[grid_pos].get("have_lamppost", false):
+			continue
+
+		_connect_lamppost_wires(grid_pos)
+
+	pending_wire_cells.clear()
+	pending_wire_cursor = 0
+
 func _generate_pieces_around_train(center: Vector2i) -> void:
 	for x in range(-eye_line, eye_line + 1):
 		for z in range(-eye_line, eye_line + 1):