feat: simplify OTA updates with timestamp

gate.lua

@@ -127,17 +127,49 @@ local function setLastUpdateVersion(v)
   if f then f.write(tostring(v)); f.close() end
 end
 
-local function runSilentGateUpdate()
-  if not fs.exists("update_gate.lua") then
-    return false, "update_gate.lua not found"
+local function checkAndApplyUpdate()
+  if type(CFG) ~= 'table' then return end
+  local remoteTs = tonumber(CFG.update_timestamp)
+  
+  if not remoteTs or remoteTs <= 0 then return end
+  
+  -- Prevent infinite reboot loops: only update once per timestamp
+  local attemptFile = ".last_update_ts"
+  if fs.exists(attemptFile) then
+    local f = fs.open(attemptFile, "r")
+    local tried = tonumber(f and f.readAll() or "0") or 0
+    if f then f.close() end
+    if tried >= remoteTs then
+      return
+    end
   end
-  local baseEnv = (getfenv and getfenv()) or _ENV or _G
-  local env = setmetatable({ AUTO_UPDATE_SILENT = true }, { __index = baseEnv })
+  
+  -- We have a NEW remote timestamp. Trigger update!
+  isUpdating = true
+  pcall(drawReadyScreen)
+  sleep(0.5)
+  
+  -- Record that we are attempting this timestamp
+  local f = fs.open(attemptFile, "w")
+  if f then f.write(tostring(remoteTs)); f.close() end
+  
+  -- Load and run update script
+  local env = setmetatable({ AUTO_UPDATE_SILENT = true }, { __index = _G or getfenv() or _ENV })
   local fn, err = loadfile("update_gate.lua", env)
-  if not fn then return false, err end
-  local ok, res = pcall(fn, "--silent")
-  if not ok then return false, tostring(res) end
-  return true, true
+  if fn then
+    local ok, res = pcall(fn, "--silent")
+    if not ok then
+      lastUpdateError = string.sub(tostring(res), 1, 30)
+    end
+  else
+    lastUpdateError = "loadfile failed: " .. tostring(err)
+  end
+  
+  isUpdating = false
+  pcall(drawReadyScreen)
+  
+  -- Reboot
+  os.reboot()
 end
 
 local function setServerConnected(ok)
@@ -422,9 +454,10 @@ end
 local function refreshRemoteLuaVersion(serverBase)
   serverBase = trim(serverBase or "")
   if #serverBase == 0 then return false end
-  local url = serverBase:gsub("/+$", "") .. "/api/public/config"
+  local url = serverBase:gsub("/+$", "") .. "/api/config?_t=" .. tostring(nowMs() + math.random(1, 999999))
   local ok, parsed = getJSON(url)
   if not ok or type(parsed) ~= "table" then return false end
+  _G.CFG = parsed
   local remote = normalizeVersionTag(type(parsed.lua_versions) == "table" and parsed.lua_versions.gate or nil)
   remoteForceUpdate = (parsed.force_update == true)
   if #remote == 0 then