fix(wget): 确保常用模块加载并改进代码执行方式

添加对常用模块的检查加载，并使用pcall安全执行下载的代码以避免直接崩溃

data/computercraft/lua/rom/programs/wget.lua

@@ -31,11 +31,19 @@ end
 
 if args[1] == "run" then
   local data = get(args[2])
-  -- 确保fs模块已加载
+  -- 确保常用模块已加载
-  if not _G.fs then
+  if not _G.fs then _G.fs = require("fs") end
-    _G.fs = require("fs")
+  if not _G.term then _G.term = require("term") end
+  if not _G.colors then _G.colors = require("colors") end
+  if not _G.textutils then _G.textutils = require("textutils") end
+  if not _G.shell then _G.shell = require("shell") end
+
+  -- 执行下载的代码
+  local func, err = load(data, "=<wget-run>", "t", _G)
+  if not func then
+    error("Failed to load downloaded code: " .. err, 0)
   end
-  assert(load(data, "=<wget-run>", "t", _G))()
+  assert(pcall(func))
 else
   local filename = args[2] or (args[1]:match("[^/]+$")) or
     error("could not determine file name", 0)