fix(android): preserve UTF-16 boundaries in notification text (#102442)

* fix(android): keep notification text UTF-16 safe

* test(android): cover UTF-16 notification boundaries

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>
Co-authored-by: Peter Steinberger <peter@steipete.me>

apps/android/app/src/main/java/ai/openclaw/app/node/DeviceNotificationListenerService.kt

@@ -27,7 +27,18 @@ private const val NOTIFICATIONS_CHANGED_EVENT = "notifications.changed"
 internal fun sanitizeNotificationText(value: CharSequence?): String? {
   val normalized = value?.toString()?.trim().orEmpty()
   // Notification extras can include long previews; cap before sending over node events.
-  return normalized.take(MAX_NOTIFICATION_TEXT_CHARS).ifEmpty { null }
+  return normalized.takeUtf16Safe(MAX_NOTIFICATION_TEXT_CHARS).ifEmpty { null }
+}
+
+private fun String.takeUtf16Safe(maxChars: Int): String {
+  if (length <= maxChars) return this
+  val end =
+    if (maxChars > 0 && Character.isHighSurrogate(this[maxChars - 1])) {
+      maxChars - 1
+    } else {
+      maxChars
+    }
+  return take(end)
 }
 
 /**

apps/android/app/src/test/java/ai/openclaw/app/node/NotificationsHandlerTest.kt

@@ -265,6 +265,18 @@ class NotificationsHandlerTest {
     assertTrue((sanitized ?: "").all { it == 'x' })
   }
 
+  @Test
+  fun sanitizeNotificationTextPreservesUtf16BoundariesAtLimit() {
+    val splitPairPrefix = "a".repeat(511)
+    assertEquals(splitPairPrefix, sanitizeNotificationText("$splitPairPrefix🚀 trailing text"))
+
+    val completePairPrefix = "a".repeat(510)
+    assertEquals(
+      "$completePairPrefix🚀",
+      sanitizeNotificationText("$completePairPrefix🚀 trailing text"),
+    )
+  }
+
   @Test
   fun notificationsActionClearablePolicy_onlyRequiresClearableForDismiss() {
     assertTrue(actionRequiresClearableNotification(NotificationActionKind.Dismiss))