chore: release version 2.3.5 and refactor lobby

Bump export_presets.cfg version to 2.3.5. Update CHANGELOG_DRAFT.md.
Refactor lobby.gd into LobbyChat, LobbyMainMenu, LobbyRoomList, LobbyRoom.
Move Nakama config to environment variables in nakama_manager.gd.
Derive auth_manager.gd encryption key from OS.get_unique_id().sha256_text().
Remove Steam email auth fallback. Require auth ticket.
Make GachaManager.pull() async in gacha_panel.gd.
Remove dummy wallet seeding. Add store_type to IAP payload.
Validate IAP receipts server-side in economy.lua.
Register gacha module in main.lua.
Clean backend_service.gd stubs.
Fix featured_banners type safety in gacha_manager.gd. Guards non-array responses.
Move tiles_armagedon_a1.res to assets/models/meshes/. Fix import fallback_path.

addons/gut/lazy_loader.gd

@@ -0,0 +1,39 @@
+@tool
+# ------------------------------------------------------------------------------
+# Static
+# ------------------------------------------------------------------------------
+static var usage_counter = load('res://addons/gut/thing_counter.gd').new()
+static var WarningsManager = load('res://addons/gut/warnings_manager.gd')
+
+static func load_all():
+	for key in usage_counter.things:
+		key.get_loaded()
+
+
+static func print_usage():
+	for key in usage_counter.things:
+		print(key._path, '  (', usage_counter.things[key], ')')
+
+
+static func clear():
+	usage_counter.things.clear()
+
+# ------------------------------------------------------------------------------
+# Class
+# ------------------------------------------------------------------------------
+var _loaded = null
+var _path = null
+
+func _init(path):
+	_path = path
+	usage_counter.add_thing_to_count(self)
+
+
+func get_loaded():
+	if(_loaded == null):
+		_loaded = WarningsManager.load_script_ignoring_all_warnings(_path)
+	usage_counter.add(self)
+	return _loaded
+
+
+