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/craftos.lua

@@ -0,0 +1,58 @@
+-- LeonOS compatibility, in theory
+
+local rc = require("rc")
+local settings = require("settings")
+
+if not settings.get("bios.compat_mode") then
+  error("compatibility mode is disabled", 0)
+end
+
+if os.version then
+  error("you are already in compatibility mode", 0)
+end
+
+local libs = {
+  "peripheral", "fs", "settings", "http", "term", "colors", "multishell",
+  "keys", "parallel", "shell", "textutils", "window", "paintutils"
+}
+
+local move = {
+  "queueEvent", "startTimer", "cancelTimer", "setAlarm", "cancelAlarm", "getComputerID",
+  "computerID", "getComputerLabel", "setComputerLabel", "computerLabel", "day", "epoch",
+  "pullEvent", "sleep"
+}
+
+local nEnv = setmetatable({}, {__index=_G})
+nEnv.os = setmetatable({}, {__index=os})
+
+for i=1, #libs, 1 do
+  nEnv[libs[i]] = select(2, pcall(require, libs[i]))
+end
+
+for i=1, #move do
+  nEnv.os[move[i]] = rc[move[i]]
+end
+
+function nEnv.printError(text)
+  io.stderr:write(text, "\n")
+end
+
+nEnv.write = rc.write
+
+nEnv.unpack = table.unpack
+if rc.lua51 then
+  for k, v in pairs(rc.lua51) do
+    nEnv[k] = v
+  end
+end
+
+nEnv.read = nEnv.term.read
+nEnv.sleep = nEnv.os.sleep
+
+function nEnv.os.version()
+  return "LeonOS 1.0 ALpha 1"
+end
+
+local func, err = loadfile("/rc/programs/shell.lua", "t", nEnv)
+if not func then error(err, 0) end
+func()