fix(ticketmachine): 修复更新触发条件并重构代码

移除未使用的 expectedMachineVersion 变量
调整后台同步任务的更新触发逻辑，仅在主页且状态有效时执行机器更新
移动版本指示器绘制函数到更早作用域，避免重复声明

ticketmachine.lua

@@ -13,7 +13,6 @@ local function jsonDecode(str)
 end
 
 local serverConnected = nil
-local expectedMachineVersion = nil
 local versionMismatch = nil
 local failedUpdateVersion = nil
 local pendingMachineUpdate = false
@@ -685,6 +684,38 @@ local function runSilentMachineUpdate()
   return true, true
 end
 
+local lastUpdateError = nil
+
+local function drawVersionIndicator()
+  if w < 1 then return end
+  local markerColor = colors.yellow
+  local markerText = '*   '
+  if isUpdating then
+    markerColor = colors.yellow
+    markerText = '^ing'
+  elseif versionMismatch == true then
+    markerColor = colors.red
+    markerText = '*   '
+  elseif versionMismatch == false then
+    markerColor = colors.lime
+    markerText = '    '
+  end
+  termDev.setBackgroundColor(colors.black)
+  termDev.setTextColor(colors.gray)
+  termDev.setCursorPos(1, 1)
+  termDev.write(tostring(VERSION))
+  termDev.setTextColor(markerColor)
+  termDev.write(markerText)
+  
+  if lastUpdateError then
+    termDev.setCursorPos(1, 2)
+    termDev.setTextColor(colors.red)
+    termDev.write(string.sub(tostring(lastUpdateError), 1, w))
+  end
+  
+  termDev.setTextColor(colors.white)
+end
+
 local function backgroundSyncTask()
   pcall(refreshConfigOnce)
   while true do
@@ -695,7 +726,7 @@ local function backgroundSyncTask()
       end
     end
 
-    if pendingMachineUpdate then
+    if pendingMachineUpdate and state and tostring(state.page or 'home') == 'home' then
       isUpdating = true
       lastUpdateError = nil
       pcall(drawVersionIndicator)
@@ -1138,38 +1169,6 @@ local function stationDisplay(code)
   return code
 end
 
-local lastUpdateError = nil
-
-local function drawVersionIndicator()
-  if w < 1 then return end
-  local markerColor = colors.yellow
-  local markerText = '*   '
-  if isUpdating then
-    markerColor = colors.yellow
-    markerText = '^ing'
-  elseif versionMismatch == true then
-    markerColor = colors.red
-    markerText = '*   '
-  elseif versionMismatch == false then
-    markerColor = colors.lime
-    markerText = '    '
-  end
-  termDev.setBackgroundColor(colors.black)
-  termDev.setTextColor(colors.gray)
-  termDev.setCursorPos(1, 1)
-  termDev.write(tostring(VERSION))
-  termDev.setTextColor(markerColor)
-  termDev.write(markerText)
-  
-  if lastUpdateError then
-    termDev.setCursorPos(1, 2)
-    termDev.setTextColor(colors.red)
-    termDev.write(string.sub(tostring(lastUpdateError), 1, w))
-  end
-  
-  termDev.setTextColor(colors.white)
-end
-
 local function drawServerStatusIndicator()
   if w < 2 then return end
   local col = colors.yellow