feat(帮助系统): 添加helplist命令用于列出所有帮助主题

添加helplist.lua程序用于列出所有可用的帮助主题，支持排序和彩色输出选项
同时添加test_helplist.lua测试脚本验证helplist命令功能

data/computercraft/lua/rom/programs/helplist.lua

@@ -0,0 +1,63 @@
+-- helplist.lua: List all available help documents
+local help = require("help")
+local textutils = require("textutils")
+local term = require("term")
+local colors = require("colors")
+
+-- Help information function
+local function printHelp()
+  print("Usage: helplist [options]")
+  print("Options:")
+  print("  --help, -h    Show this help message")
+  print("  --sort, -s    Sort topics alphabetically")
+  print("  --color, -c   Show colored output")
+  print([[
+Lists all available help topics in LeonOS.]])
+end
+
+-- Main function
+local function main(args)
+  -- Process command line arguments
+  local showHelp = false
+  local sortTopics = false
+  local useColor = false
+
+  for _, arg in ipairs(args) do
+    if arg == "--help" or arg == "-h" then
+      showHelp = true
+    elseif arg == "--sort" or arg == "-s" then
+      sortTopics = true
+    elseif arg == "--color" or arg == "-c" then
+      useColor = true
+    end
+  end
+
+  if showHelp then
+    printHelp()
+    return
+  end
+
+  -- Get all help topics
+  local topics = help.topics()
+
+  -- Sort topics if requested
+  if sortTopics then
+    table.sort(topics)
+  end
+
+  -- Display the help topics
+  print("Available help topics (" .. #topics .. "):")
+  for _, topic in ipairs(topics) do
+    if useColor then
+      term.setTextColor(colors.cyan)
+      print("  " .. topic)
+      term.setTextColor(colors.white)
+    else
+      print("  " .. topic)
+    end
+  end
+end
+
+-- Run the main function
+local args = {...}
+main(args)