feat: 初始提交 LeonOS 实现

添加 LeonOS 的基本实现，包括：
- 核心 API 模块（colors, disk, gps, keys, multishell, parallel, rednet, redstone, settings, vector）
- 命令行程序（about, alias, bg, clear, copy, delete, edit, fg, help, list, lua, mkdir, move, paint, peripherals, programs, reboot, set, shutdown, threads）
- 系统启动脚本和包管理
- 文档（README.md, LICENSE）
- 开发工具（devbin）和更新程序

实现功能：
- 完整的线程管理系统
- 兼容 ComputerCraft 的 API 设计
- 改进的 shell 和命令补全系统
- 多标签终端支持
- 设置管理系统

data/computercraft/lua/rom/programs/set.lua

@@ -0,0 +1,47 @@
+-- 'set' program
+
+local colors = require("colors")
+local settings = require("settings")
+local textutils = require("textutils")
+
+local args = {...}
+
+local function coerce(val)
+  if val == "nil" then
+    return nil
+  elseif val == "false" then
+    return false
+  elseif val == "true" then
+    return true
+  else
+    return tonumber(val) or val
+  end
+end
+
+local col = {
+  string = colors.red,
+  table = colors.green,
+  number = colors.magenta,
+  boolean = colors.lightGray
+}
+
+if #args == 0 then
+  for _, setting in ipairs(settings.getNames()) do
+    local value = settings.get(setting)
+    textutils.coloredPrint(colors.cyan, setting, colors.white, " is ",
+      col[type(value)], string.format("%q", value))
+  end
+elseif #args == 1 then
+  local setting = args[1]
+  local value = settings.get(setting)
+  textutils.coloredPrint(colors.cyan, setting, colors.white, " is ",
+    col[type(value)], string.format("%q", value))
+  local def = settings.getDetails(setting)
+  if def then
+    print(def.description)
+  end
+else
+  local setting, value = args[1], args[2]
+  settings.set(setting, coerce(value))
+  settings.save()
+end