fix onColumnProposeMove rowMarkerOffset (#962)

* fix onColumnProposeMove rowMarkerOffset

* fix test

* only forward boolean instead of coercing

[copilot]: Comparing the result to === false forces a boolean return and inverts or masks the original callback semantics. Instead, forward the actual return value (or undefined) from onColumnProposeMove so consumers can cancel by returning false and allow by returning true or nothing.

Co-authored-by: Copilot <[email protected]>

* coerce boolean for types but invert

---------

Co-authored-by: Copilot <[email protected]>

Author: BrianHung

packages/core/src/data-editor/data-editor.tsx

@@ -2528,6 +2528,16 @@ const DataEditorImpl: React.ForwardRefRenderFunction<DataEditorRef, DataEditorPr
         ]
     );
 
+    const onColumnProposeMoveImpl = whenDefined(
+        onColumnProposeMove,
+        React.useCallback(
+            (startIndex: number, endIndex: number) => {
+                return onColumnProposeMove?.(startIndex - rowMarkerOffset, endIndex - rowMarkerOffset) !== false;
+            },
+            [onColumnProposeMove, rowMarkerOffset]
+        )
+    );
+
     const onColumnMovedImpl = whenDefined(
         onColumnMoved,
         React.useCallback(
@@ -4052,7 +4062,7 @@ const DataEditorImpl: React.ForwardRefRenderFunction<DataEditorRef, DataEditorPr
                     columns={mangledCols}
                     nonGrowWidth={nonGrowWidth}
                     drawHeader={drawHeader}
-                    onColumnProposeMove={onColumnProposeMove}
+                    onColumnProposeMove={onColumnProposeMoveImpl}
                     drawCell={drawCell}
                     disabledRows={disabledRows}
                     freezeColumns={mangledFreezeColumns}