fix(web, ticketmachine): 修复web设备ID匹配，清理无用代码并优化界面显示

调整web端设备ID匹配正则，支持带#前缀的数字ID
移除ticketmachine.lua中未使用的变量和工具函数
替换界面成本显示文本，将$改为cogs:

ticketmachine.lua

@@ -12,8 +12,6 @@ local function jsonDecode(str)
 end
 
 local serverConnected = nil
-local serverLastChangeTs = 0
-local expectedMachineVersion = nil
 local versionMismatch = nil
 
 local function normalizeVersionTag(v)
@@ -1227,7 +1225,7 @@ local function showSingleSegmentSelection()
       local x = colIdx == 0 and bx1 or bx2
       local y = by + rowIdx * 4
       
-      local label = seg.lineName .. ' $' .. tostring(seg.cost)
+      local label = seg.lineName .. ' cogs:' .. tostring(seg.cost)
       if #label > bw then label = label:sub(1, bw) end
       local isSelected = (state.singleSegment == seg)
       addButton(x, y, label, bw, 3, {isSelected and colors.green or colors.blue, colors.white}, function()
@@ -2159,25 +2157,6 @@ local function generateTicketId()
   return generateNumericCode('TK', 8)
 end
 
-local function ensureTicketIdFormat(id)
-  if id == nil then return '' end
-  local s = tostring(id)
-  s = s:gsub('%s+', '')
-  if #s == 0 then return '' end
-  local prefix, num = s:match('^([A-Za-z][A-Za-z])%-?([0-9]+)$')
-  if prefix and num then
-    prefix = prefix:upper()
-    if #num < 8 then
-      num = string.rep('0', 8 - #num) .. num
-    elseif #num > 8 then
-      num = num:sub(-8)
-    end
-    return prefix .. '-' .. num
-  end
-  return s:lower()
-end
-
-
 
 local function showDone()
   if state.productMode == 'card' then