voice: fix waveform — pointerInput on Box, cursor + white bars stay on pause

- Canvas pointerInput moved to wrapping Box (state updates trigger recomposition)
- showCursor = playing || paused (cursor and white bars visible on pause)
- elapsed/dur stays visible on pause too

tools/chatgui-android/app/src/main/java/com/utun/chat/ui/components/MessageBubble.kt

@@ -129,7 +129,8 @@ private fun VoiceBubble(message: Message, textColor: Color,
 
             /* Waveform with seek on tap */
             if (wfCount >= 2) {
-                Canvas(modifier = Modifier.weight(1f).height(28.dp)
+                Box(
+                    modifier = Modifier.weight(1f).height(28.dp)
                         .pointerInput(message.filePath) {
                             detectTapGestures { offset ->
                                 if (message.filePath.isEmpty()) return@detectTapGestures
@@ -140,9 +141,10 @@ private fun VoiceBubble(message: Message, textColor: Color,
                             }
                         }
                 ) {
+                    Canvas(modifier = Modifier.fillMaxSize()) {
                         val barW = size.width / wfCount
                         val ph = size.height
-                    val showCursor = playing && !paused
+                        val showCursor = playing || paused
                         val playedIdx = if (showCursor && progress > 0f) (progress * wfCount).toInt() else 0
                         for (i in 0 until wfCount) {
                             val level = wf[i].coerceIn(0f, 1f)
@@ -163,6 +165,7 @@ private fun VoiceBubble(message: Message, textColor: Color,
                     }
                 }
             }
+        }
 
         Spacer(Modifier.height(4.dp))
 
@@ -173,7 +176,7 @@ private fun VoiceBubble(message: Message, textColor: Color,
             verticalAlignment = Alignment.Bottom
         ) {
             Text(
-                if (playing && !paused) "${formatDurationMs(elapsedMs)} / ${formatDurationMs(durMs)}"
+                if (playing || paused) "${formatDurationMs(elapsedMs)} / ${formatDurationMs(durMs)}"
                 else formatDurationMs(durMs),
                 fontSize = 12.sp,
                 color = textColor.copy(alpha = 0.55f)