feat: restructure Leave Server section with improved layout and visual hierarchy

CollabTableAndroid/app/src/main/java/com/collabtable/app/ui/screens/SettingsScreen.kt

@@ -307,7 +307,19 @@ fun SettingsScreen(
                 }
             }
 
-            // Leave Server button relocated below Diagnostics section
+            // Leave Server section
+            Text(
+                text = "Leave Server",
+                style = MaterialTheme.typography.titleMedium,
+            )
+            Card(
+                modifier = Modifier.fillMaxWidth(),
+                colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surfaceVariant),
+            ) {
+                Column(
+                    modifier = Modifier.padding(12.dp),
+                    verticalArrangement = Arrangement.spacedBy(8.dp),
+                ) {
                     Button(
                         onClick = { showLeaveDialog = true },
                         modifier = Modifier.fillMaxWidth(),
@@ -330,6 +342,8 @@ fun SettingsScreen(
                             Text("Leave Server")
                         }
                     }
+                }
+            }
 
             Card(
                 modifier = Modifier.fillMaxWidth(),