feat: update FAB bottom padding logic in GroupSetupScreen to improve positioning with keyboard and emoji panel

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

@@ -226,14 +226,15 @@ fun GroupSetupScreen(
     val density = LocalDensity.current
     val imeBottomPx = WindowInsets.ime.getBottom(density)
     val imeBottomDp = with(density) { imeBottomPx.toDp() }
+    // FAB bottom padding: keep FAB at a consistent visual position above any keyboard.
+    // When emoji panel is shown → it's part of Scaffold bottomBar, paddingValues includes it,
+    // so we offset from the *content area* bottom which is already above the emoji panel.
+    // When IME is shown → paddingValues don't include IME, so we add imeBottomDp.
+    // When neither → just a small offset from the bottom.
     val fabBottomPadding =
         if (coordinator.isEmojiBoxVisible) {
-            // Emoji panel is shown as Scaffold bottomBar → paddingValues already
-            // reserves space for it, so FAB only needs a small offset above it.
             14.dp
         } else if (imeBottomDp > 0.dp) {
-            // System keyboard is open but NOT covered by paddingValues.
-            // Place FAB at the same visual position as with the emoji panel.
             14.dp + imeBottomDp
         } else {
             18.dp