fix: 修复安装程序版本号并添加fs模块引用

更新安装程序版本号至0.3.6 Beta 3
在app.lua中添加fs模块引用以支持文件系统操作

data/computercraft/lua/rom/programs/app.lua

@@ -1,5 +1,5 @@
 -- app.lua - Application launcher for LeonOS
-
+local fs = require("fs")
 local function show_help()
   print("Usage: app <program_name> [arguments]")
   print("Runs an application from the /app directory")

installer.lua

@@ -1,5 +1,5 @@
 -- LeonOS installer
-local INSTALLER_VERSION = "0.3.6 Beta 2"
+local INSTALLER_VERSION = "0.3.6 Beta 3"
 local DEFAULT_ROM_DIR = "/leonos"
 
 print("Start loading LeonOS installer ("..INSTALLER_VERSION..")...")
@@ -43,6 +43,7 @@ print("[Installer] Loading done.")
 print("[Installer] Loading module 6")
 local json = ghload("rxi/json.lua/master/json.lua", "ghload(json)")
 package.loaded["rc.json"] = json
+print("[Installer] Loading done.")
 print("[Installer] Loading module 7")
 local function rcload(f)
   return ghload(