feat: add silent auto-check for app updates on launch

app/src/main/java/com/catlas/escapepenacony/ui/MainScreen.kt

@@ -81,6 +81,17 @@ fun MainScreen(
         if (directMode != DirectModeType.NONE) {
             currentActiveConfig = StorageManager.readConfigViaDirect(directMode)
         }
+
+        // Silent auto-check for APK updates in background on app launch
+        coroutineScope.launch {
+            val res = UpdateManager.checkForAppUpdate()
+            res.onSuccess { info ->
+                if (info != null && info.isNewer) {
+                    releaseInfo = info
+                    showUpdateDialog = true
+                }
+            }
+        }
     }
 
     // Refresh when Shizuku permission is granted via popup