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/apis/rednet.lua

@@ -0,0 +1,113 @@
+-- rc.rednet
+
+local expect = require("cc.expect").expect
+local peripheral = require("peripheral")
+
+local rednet = {
+  CHANNEL_BROADCAST = 65535,
+  CHANNEL_REPEAT    = 65533,
+  MAX_ID_CHANNELS   = 65500,
+}
+
+local opened = {}
+function rednet.open(modem)
+  expect(1, modem, "string")
+  peripheral.call(modem, "open", os.computerID())
+  peripheral.call(modem, "open", rednet.CHANNEL_BROADCAST)
+  opened[modem] = true
+end
+
+local function call(method, modem, erase, passids, ...)
+  local ret = false
+  if modem then
+    if erase then opened[modem] = false end
+    if passids then
+      ret = ret or peripheral.call(modem, method, os.computerID(), ...)
+      ret = ret or peripheral.call(modem, method, rednet.CHANNEL_BROADCAST, ...)
+    else
+      ret = peripheral.call(modem, method, ...)
+    end
+
+  else
+    for k in pairs(opened) do
+      ret = ret or call(k, method, erase, passids, ...)
+    end
+  end
+  return ret
+end
+
+function rednet.close(modem)
+  expect(1, modem, "string", "nil")
+  return call("close", modem, true, true)
+end
+
+function rednet.isOpen(modem)
+  expect(1, modem, "string", "nil")
+  return call("isOpen", modem, false, true)
+end
+
+function rednet.send(to, message, protocol)
+  expect(1, to, "number")
+  expect(2, message, "string", "table", "number", "boolean")
+  expect(3, protocol, "string", "nil")
+
+  if type(message) == "table" then
+    if protocol then table.insert(message, 1, protocol) end
+    table.insert(message, 1, "rednet_message")
+  else
+    message = {"rednet_message", to, message, protocol}
+  end
+  call("transmit", nil, false, false, rednet.CHANNEL_BROADCAST,
+    os.computerID(), message)
+  return rednet.isOpen()
+end
+
+function rednet.broadcast(message, protocol)
+  expect(1, message, "string", "table", "number", "boolean")
+  expect(2, protocol, "string", "nil")
+  call("transmit", nil, false, false, rednet.CHANNEL_BROADCAST,
+    rednet.CHANNEL_BROADCAST, message)
+end
+
+function rednet.receive(protocol, timeout)
+  expect(1, protocol, "string", "nil")
+  timeout = expect(2, timeout, "number", "nil") or math.huge
+
+  local timer
+  if timeout then
+    timer = os.startTimer(timer)
+  end
+
+  while true do
+    local event = table.pack(os.pullEvent())
+    if event[1] == "timer" and event[2] == timer then return end
+    if event[1] == "rednet_message" and (event[4] == protocol or
+        not protocol) then
+      return table.unpack(event, 2)
+    end
+  end
+end
+
+local running = false
+function rednet.run()
+  if running then
+    error("rednet is already running")
+  end
+
+  running = true
+
+  while true do
+    local event = table.pack(os.pullEvent())
+    if event[1] == "modem_message" then
+      local message = event[5]
+      if type(message) == "table" then
+        if message[1] == "rednet_message" and (message[2] == os.computerID() or
+            message[2] == rednet.CHANNEL_BROADCAST) then
+          os.queueEvent("rednet_message", event[3], message[2], message[3])
+        end
+      end
+    end
+  end
+end
+
+return rednet