feat(自动更新): 添加持久化版本追踪避免重复更新

新增读写本地版本记录文件的工具函数，调整自动更新触发逻辑仅在版本不一致时触发，更新成功后写入版本号；修复更新失败版本号的赋值问题，同时为安装脚本添加标准文件头注释

gate.lua

@@ -113,6 +113,20 @@ local function isGateIdleForUpdate()
   return nowMs() >= gateBusyUntilTs
 end
 
+local function getLastUpdateVersion()
+  if not fs.exists(".last_update_version") then return nil end
+  local f = fs.open(".last_update_version", "r")
+  if not f then return nil end
+  local v = f.readAll()
+  f.close()
+  return v
+end
+
+local function setLastUpdateVersion(v)
+  local f = fs.open(".last_update_version", "w")
+  if f then f.write(tostring(v)); f.close() end
+end
+
 local function runSilentGateUpdate()
   local baseEnv = (getfenv and getfenv()) or _ENV or _G
   local env = setmetatable({ AUTO_UPDATE_SILENT = true }, { __index = baseEnv })
@@ -1430,8 +1444,8 @@ while true do
     pcall(function()
       refreshRemoteLuaVersion(guessBaseFromStatusURL(serverURL))
     end)
-    if remoteForceUpdate and versionMismatch == true then
-      if expectedGateVersion ~= failedUpdateVersion then
+    if remoteForceUpdate then
+      if expectedGateVersion and expectedGateVersion ~= getLastUpdateVersion() and expectedGateVersion ~= failedUpdateVersion then
         pendingGateUpdate = true
       end
     end
@@ -1442,6 +1456,7 @@ while true do
       os.sleep(0.5)
       local ok, updated = pcall(runSilentGateUpdate)
       if ok and updated then
+        if expectedGateVersion then setLastUpdateVersion(expectedGateVersion) end
         os.reboot()
         return
       end