chore(station_broadcast): 升级版本至v1.0.49并调整ETA触发阈值

调整列车接近播报的ETA更新阈值，从3秒改为15秒以减少频繁触发

station_broadcast.lua

@@ -1,6 +1,6 @@
 
 -- 1. Configuration & Constants
-local APP_VERSION_TEXT = "v1.0.48"
+local APP_VERSION_TEXT = "v1.0.49"
 
 local CONFIG = {
     CLOUD_URL = "ws://stabadmin.fse-media.group",
@@ -2705,7 +2705,7 @@ function Main.loop()
                             if not pending then
                                 State.pendingApproaching[announceKey] = { since = now, lastEta = etaSeconds }
                             else
-                                if etaSeconds > (tonumber(pending.lastEta) or etaSeconds) + 3 then
+                                if etaSeconds > (tonumber(pending.lastEta) or etaSeconds) + 15 then
                                     pending.since = now
                                 end
                                 pending.lastEta = etaSeconds