fix(remote): forward create index replace policy

rust/lancedb/src/remote/table.rs

@@ -527,6 +527,10 @@ impl<S: HttpSend> RemoteTable<S> {
             "column": canonical_column
         });
 
+        if !index.replace {
+            body["replace"] = false.into();
+        }
+
         // Add name parameter if provided (for backwards compatibility, only include if Some)
         if let Some(ref name) = index.name {
             body["name"] = serde_json::Value::String(name.clone());
@@ -6077,6 +6081,40 @@ mod tests {
         }
     }
 
+    #[tokio::test]
+    async fn test_create_index_forwards_replace_false() {
+        let table = Table::new_with_handler("my_table", move |request| {
+            assert_eq!(request.method(), "POST");
+            match request.url().path() {
+                "/v1/table/my_table/describe/" => {
+                    let schema = Schema::new(vec![Field::new("a", DataType::Int32, false)]);
+                    http::Response::builder()
+                        .status(200)
+                        .body(describe_response(&schema))
+                        .unwrap()
+                }
+                "/v1/table/my_table/create_index/" => {
+                    let body = request.body().unwrap().as_bytes().unwrap();
+                    let body: serde_json::Value = serde_json::from_slice(body).unwrap();
+                    assert_eq!(body["replace"], json!(false));
+
+                    http::Response::builder()
+                        .status(200)
+                        .body("{}".to_string())
+                        .unwrap()
+                }
+                path => panic!("Unexpected path: {}", path),
+            }
+        });
+
+        table
+            .create_index(&["a"], Index::BTree(Default::default()))
+            .replace(false)
+            .execute()
+            .await
+            .unwrap();
+    }
+
     #[tokio::test]
     async fn test_create_index_returns_job() {
         let describe_calls = std::sync::Arc::new(std::sync::atomic::AtomicUsize::new(0));