feat: enhance keyboard height management and emoji picker synchronization in GroupSetupScreen

app/src/main/java/com/rosetta/messenger/ui/chats/GroupSetupScreen.kt

@@ -7,6 +7,8 @@ import android.view.inputmethod.InputMethodManager
 import androidx.activity.compose.BackHandler
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
@@ -243,15 +245,28 @@ fun GroupSetupScreen(
     }
 
     var lastStableKeyboardHeight by remember { mutableStateOf(0.dp) }
+    var isKeyboardVisible by remember { mutableStateOf(false) }
     LaunchedEffect(imeBottomPx) {
         val currentImeHeight = with(density) { imeBottomPx.toDp() }
         coordinator.updateKeyboardHeight(currentImeHeight)
+        isKeyboardVisible = currentImeHeight > 50.dp
         if (currentImeHeight > 100.dp) {
             coordinator.syncHeights()
             lastStableKeyboardHeight = currentImeHeight
         }
     }
 
+    // Save keyboard height for emoji picker sync
+    LaunchedEffect(isKeyboardVisible, showEmojiKeyboard) {
+        if (isKeyboardVisible && !showEmojiKeyboard) {
+            kotlinx.coroutines.delay(350)
+            if (isKeyboardVisible && !showEmojiKeyboard && lastStableKeyboardHeight > 300.dp) {
+                val heightPx = with(density) { lastStableKeyboardHeight.toPx().toInt() }
+                KeyboardHeightProvider.saveKeyboardHeight(context, heightPx)
+            }
+        }
+    }
+
     fun toggleEmojiPicker() {
         val now = System.currentTimeMillis()
         if (now - lastToggleTime < toggleCooldownMs || step != GroupSetupStep.DETAILS || isLoading) return
@@ -725,22 +740,24 @@ fun GroupSetupScreen(
                 containerColor = if (actionEnabled) accentColor else accentColor.copy(alpha = 0.42f),
                 contentColor = Color.White,
                 shape = CircleShape,
-                modifier =
+                modifier = run {
+                    var lastStableFabBottom by remember { mutableStateOf(18.dp) }
+                    val rawBottom = if (imeBottomDp > 0.dp) {
+                        imeBottomDp + 14.dp
+                    } else if (coordinator.isEmojiBoxVisible && coordinator.emojiHeight > 0.dp) {
+                        coordinator.emojiHeight + 14.dp
+                    } else {
+                        18.dp
+                    }
+                    // During keyboard switch, keep FAB at last stable position
+                    if (!coordinator.isTransitioning) {
+                        lastStableFabBottom = rawBottom
+                    }
                     Modifier
                         .align(Alignment.BottomEnd)
-                        .padding(
-                            end = 16.dp,
-                            // Consistent: always 14dp above whichever keyboard is showing.
-                            // This Box ignores paddingValues, so we measure from raw screen bottom.
-                            bottom = if (imeBottomDp > 0.dp) {
-                                imeBottomDp + 14.dp
-                            } else if (coordinator.isEmojiBoxVisible && coordinator.emojiHeight > 0.dp) {
-                                coordinator.emojiHeight + 14.dp
-                            } else {
-                                18.dp
-                            }
-                        )
+                        .padding(end = 16.dp, bottom = lastStableFabBottom)
                         .size(58.dp)
+                }
             ) {
                 if (isLoading && step == GroupSetupStep.DESCRIPTION) {
                     CircularProgressIndicator(