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/settings.lua

@@ -0,0 +1,114 @@
+-- rc.settings
+
+local expect = require("cc.expect")
+local textutils = require("textutils")
+
+local settings = {}
+local defs = {}
+local set = {}
+
+function settings.define(name, opts)
+  expect.expect(1, name, "string")
+  expect.expect(2, opts, "table", "nil")
+
+  opts = opts or {}
+  opts.description = expect.field(opts, "description", "string", "nil")
+  opts.type = expect.field(opts, "type", "string", "nil")
+  defs[name] = opts
+end
+
+function settings.undefine(name)
+  expect.expect(1, name, "string")
+  defs[name] = nil
+end
+
+function settings.set(name, value)
+  expect.expect(1, name, "string")
+
+  if defs[name] and defs[name].type then
+    expect.expect(2, value, defs[name].type)
+  else
+    expect.expect(2, value, "number", "string", "boolean")
+  end
+
+  set[name] = value
+end
+
+function settings.get(name, default)
+  expect.expect(1, name, "string")
+  if set[name] ~= nil then
+    return set[name]
+  elseif default ~= nil then
+    return default
+  else
+    return defs[name] and defs[name].default
+  end
+end
+
+function settings.getDetails(name)
+  expect.expect(1, name, "string")
+  local def = defs[name]
+  if not def then return end
+  return {
+    description = def.description,
+    default = def.default,
+    value = set[name],
+    type = def.type,
+  }
+end
+
+function settings.unset(name)
+  expect.expect(1, name, "string")
+  set[name] = nil
+end
+
+function settings.clear()
+  set = {}
+end
+
+function settings.getNames()
+  local names = {}
+  for k in pairs(defs) do
+    names[#names+1] = k
+  end
+  table.sort(names)
+  return names
+end
+
+function settings.load(path)
+  expect.expect(1, path, "string", "nil")
+
+  path = path or ".settings"
+  local handle = io.open(path, "r")
+  if not handle then
+    return false
+  end
+
+  local data = handle:read("a")
+  handle:close()
+
+  local new = textutils.unserialize(data)
+  if not new then return false end
+  for k, v in pairs(new) do
+    set[k] = v
+  end
+
+  return true
+end
+
+function settings.save(path)
+  expect.expect(1, path, "string", "nil")
+
+  path = path or ".settings"
+  local data = textutils.serialize(set)
+
+  local handle = io.open(path, "w")
+  if not handle then return false end
+
+  handle:write(data)
+  handle:close()
+
+  return true
+end
+
+return settings