feat(包管理器): 实现LeonOS包管理系统基础功能

添加包管理器核心程序(pkg.lua)及相关支持文件
- 实现包安装、更新、移除、列表、搜索等功能
- 添加包元数据结构和本地存储管理
- 包含示例包和命令补全支持
- 更新系统版本至0.3.0

data/computercraft/lua/rom/completions/pkg.lua

@@ -0,0 +1,31 @@
+-- pkg command completion
+local shell = require("shell")
+local completion = require("cc.shell.completion")
+
+-- 定义pkg命令的补全函数
+local function pkg_completion(shell, index, text, previous)
+  -- 子命令补全
+  if index == 1 then
+    return completion.choice(text, {"install", "update", "remove", "list", "search", "info", "help"})
+  end
+
+  -- 选项补全 (--force, --local)
+  if text:sub(1, 2) == "--" then
+    return completion.choice(text, {"--force", "--local"})
+  end
+
+  -- 命令特定补全
+  local command = previous[1]
+  if command == "install" or command == "update" or command == "remove" or command == "info" then
+    -- 这里可以添加包名补全逻辑
+    -- 目前返回空列表
+    return {}
+  elseif command == "search" then
+    -- 搜索查询不需要特定补全
+    return {}
+  end
+
+  return {}
+end
+
+shell.setCompletionFunction("pkg", pkg_completion)

data/computercraft/lua/rom/completions/tree.lua

@@ -0,0 +1,7 @@
+-- tree command completion
+local shell = require("shell")
+local completion = require("cc.shell.completion")
+
+shell.setCompletionFunction("tree", completion.build(
+  {completion.dir, many = true}
+))