feat: simplify OTA updates with timestamp

ticketmachine.lua

@@ -14,8 +14,6 @@ end
 
 local serverConnected = nil
 local versionMismatch = nil
-local failedUpdateVersion = nil
-local pendingMachineUpdate = false
 local isUpdating = false
 local state = {}
 
@@ -716,31 +714,49 @@ local function drawVersionIndicator()
   termDev.setTextColor(colors.white)
 end
 
+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
+  
+  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
+  isUpdating = true
+  pcall(drawVersionIndicator)
+  sleep(0.5)
+  
+  local f = fs.open(attemptFile, "w")
+  if f then f.write(tostring(remoteTs)); f.close() end
+  
+  local env = setmetatable({ AUTO_UPDATE_SILENT = true }, { __index = _G or getfenv() or _ENV })
+  local fn, err = loadfile("update_machine.lua", env)
+  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(drawVersionIndicator)
+  
+  os.reboot()
+end
+
 local function backgroundSyncTask()
   pcall(refreshConfigOnce)
   while true do
-    if type(CFG) == 'table' and type(CFG.force_update) == 'boolean' and CFG.force_update == true and versionMismatch == true then
-      isUpdating = true
-      pcall(drawVersionIndicator)
-      sleep(0.5)
-      
-      -- Extreme fallback: just run the update script directly
-      local baseEnv = (getfenv and getfenv()) or _ENV or _G
-      local env = setmetatable({ AUTO_UPDATE_SILENT = true }, { __index = baseEnv })
-      local fn = loadfile('update_machine.lua', env)
-      if fn then
-        local ok, err = pcall(fn, '--silent')
-        if not ok then
-          lastUpdateError = string.sub(tostring(err), 1, 30)
-        end
-      else
-        lastUpdateError = "loadfile failed"
-      end
-      
-      isUpdating = false
-      pcall(drawVersionIndicator)
-      sleep(10) -- Sleep 10s to prevent spamming
-    end
+    pcall(checkAndApplyUpdate)
     sleep(UPDATE_CHECK_INTERVAL)
     pcall(refreshConfigOnce)
   end
@@ -910,7 +926,7 @@ local function sameLogicalStation(a, b)
 end
 
 local function fetchConfig()
-  local txt = fetchHTTP(API_BASE .. '/config')
+  local txt = fetchHTTP(API_BASE .. '/config?_t=' .. tostring(os.epoch and os.epoch("utc") or math.random(1, 999999)))
   return txt and jsonDecode(txt) or nil
 end
 
@@ -1033,7 +1049,7 @@ local function waitButtons()
         end
       end
     elseif ev == 'trigger_update' then
-      pendingMachineUpdate = true
+      -- obsolete
     elseif ev == 'config_updated' then
       if state and state.page == 'home' then return end
     end