Use HorizontalDivider instead of deprecated Divider

app/src/main/java/com/bitchat/android/ui/ChatScreen.kt

@@ -210,7 +210,7 @@ private fun ChatInputSection(
         shadowElevation = 8.dp
     ) {
         Column {
-            Divider(color = colorScheme.outline.copy(alpha = 0.3f))
+            HorizontalDivider(color = colorScheme.outline.copy(alpha = 0.3f))
             
             // Command suggestions box
             if (showCommandSuggestions && commandSuggestions.isNotEmpty()) {
@@ -220,7 +220,7 @@ private fun ChatInputSection(
                     modifier = Modifier.fillMaxWidth()
                 )
 
-                Divider(color = colorScheme.outline.copy(alpha = 0.2f))
+                HorizontalDivider(color = colorScheme.outline.copy(alpha = 0.2f))
             }
             
             MessageInput(
@@ -283,12 +283,12 @@ private fun ChatFloatingHeader(
     }
     
     // Divider under header
-    Divider(
+    HorizontalDivider(
-        color = colorScheme.outline.copy(alpha = 0.3f),
         modifier = Modifier
             .fillMaxWidth()
             .offset(y = headerHeight)
-            .zIndex(1f)
+            .zIndex(1f),
+        color = colorScheme.outline.copy(alpha = 0.3f)
     )
 }
 

app/src/main/java/com/bitchat/android/ui/SidebarComponents.kt

@@ -74,7 +74,7 @@ fun SidebarOverlay(
             ) {
                 SidebarHeader()
 
-                Divider()
+                HorizontalDivider()
                 
                 // Scrollable content
                 LazyColumn(
@@ -101,7 +101,7 @@ fun SidebarOverlay(
                         }
                         
                         item {
-                            Divider(modifier = Modifier.padding(vertical = 4.dp))
+                            HorizontalDivider(modifier = Modifier.padding(vertical = 4.dp))
                         }
                     }