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/update.lua

@@ -0,0 +1,63 @@
+-- update: download a new copy of LeonOS
+
+local rc = require("rc")
+local term = require("term")
+local colors = require("colors")
+local textutils = require("textutils")
+
+if not package.loaded.http then
+  io.stderr:write("The HTTP API is disabled and the updater cannot continue.  Please enable the HTTP API in the ComputerCraft configuration and try again.\n")
+  return
+end
+
+term.at(1,1).clear()
+
+textutils.coloredPrint(colors.yellow,
+  "LeonOS Updater (Stage 1)\n===========================")
+
+print("Checking for update...")
+
+local http = require("http")
+local base = "https://raw.githubusercontent.com/LeonMMcoset/LeonOS/primary/"
+
+local Bhandle, Berr = http.get(base .. "data/computercraft/lua/bios.lua")
+if not Bhandle then
+  error(Berr, 0)
+end
+
+local first = Bhandle.readLine()
+Bhandle.close()
+
+local oldVersion = rc.version():gsub("LeonOS ", "")
+local newVersion = first:match("LeonOS v?(%d+.%d+.%d+)")
+
+if newVersion and (oldVersion ~= newVersion) or (...) == "-f" then
+  textutils.coloredPrint(colors.green, "Found", colors.white, ": ",
+    colors.red, oldVersion, colors.yellow, " -> ", colors.lime,
+    newVersion or oldVersion)
+
+  io.write("Apply update? [y/N]: ")
+  if io.read() ~= "y" then
+    textutils.coloredPrint(colors.red, "Not applying update.")
+    return
+  end
+
+  textutils.coloredPrint(colors.green, "Applying update.")
+  local handle, err = http.get(base.."updater.lua", nil, true)
+  if not handle then
+    error("Failed downloading stage 2: " .. err, 0)
+  end
+
+  local data = handle.readAll()
+  handle.close()
+
+  local out = io.open("/.start_rc.lua", "w")
+  out:write(data)
+  out:close()
+
+  textutils.coloredWrite(colors.yellow, "Restarting...")
+  rc.sleep(3)
+  rc.reboot()
+else
+  textutils.coloredPrint(colors.red, "None found")
+end