fix(gate): 修复缺失的 splitDisplayLines 函数定义导致的启动崩溃

- 添加 splitDisplayLines 函数，用于按换行符拆分多行显示文本
- 处理 nil 输入、空字符串及无换行场景的边界情况
- 版本号从 v1.5.30 升级至 v1.5.31

gate.lua

@@ -1,7 +1,7 @@
 local DEFAULT_SERVER_BASE = "https://ticket.fse-media.group"
 local DEFAULT_SERVER_PATH = "/api/tickets/check"
 local GATE_OPEN_SECONDS = 2
-local VERSION = "v1.5.30"
+local VERSION = "v1.5.31"
 local VERSION_CHECK_INTERVAL = 5
 local PERIPHERAL_WAIT_INTERVAL = 0.5
 local PERIPHERAL_WAIT_MAX_RETRIES = 40
@@ -440,6 +440,18 @@ end
 
 local _cachedDrawArgHash = nil
 
+local function splitDisplayLines(s)
+  if s == nil then return {} end
+  local str = tostring(s)
+  if #trim(str) == 0 then return {} end
+  local lines = {}
+  for line in str:gmatch("[^\n]+") do
+    table.insert(lines, line)
+  end
+  if #lines == 0 then table.insert(lines, str) end
+  return lines
+end
+
 local function draw(statusLine1, statusLine2, statusColor)
   clear()
   if not termDev then return end