fix(chat): scope table Add-to-chat to a column-header selection's columns

Cursor: a column-header selection set contextMenuColumnIds to undefined, so
Add-to-chat sent every column (full-row dump). A column selection spans all
rows of the chosen columns, so treat it like a cell range and carry those
column ids.

Author: mzxchandra

apps/sim/app/workspace/[workspaceId]/tables/[tableId]/components/table-grid/table-grid.tsx

@@ -3690,10 +3690,11 @@ export function TableGrid({
     : contextMenuRowIds.length || 1
 
   /**
-   * Column ids for an "Add to chat" table selection. Only a spreadsheet-style
-   * cell range narrows the columns; whole-row (gutter) selections and single
-   * rows send every column (undefined). A range spanning all columns is
-   * equivalent to whole rows, so it also collapses to undefined.
+   * Column ids for an "Add to chat" table selection. A spreadsheet-style cell
+   * range AND a column-header selection (which spans every row of the chosen
+   * columns) narrow the columns; whole-row (gutter) selections and single rows
+   * send every column (undefined). A range spanning all columns is equivalent to
+   * whole rows, so it also collapses to undefined.
    */
   const contextMenuColumnIds = useMemo<string[] | undefined>(() => {
     if (!contextMenu.isOpen || !contextMenu.row) return undefined
@@ -3704,7 +3705,7 @@ export function TableGrid({
       return undefined
     }
     const sel = normalizedSelection
-    if (!sel || isColumnSelection) return undefined
+    if (!sel) return undefined
     const contextRowArrayIndex = rows.findIndex((r) => r.id === contextMenu.row!.id)
     if (contextRowArrayIndex < sel.startRow || contextRowArrayIndex > sel.endRow) return undefined
     const ids: string[] = []
@@ -3713,15 +3714,7 @@ export function TableGrid({
       if (col) ids.push(getColumnId(col))
     }
     return ids.length > 0 && ids.length < displayColumns.length ? ids : undefined
-  }, [
-    contextMenu.isOpen,
-    contextMenu.row,
-    rowSelection,
-    normalizedSelection,
-    isColumnSelection,
-    rows,
-    displayColumns,
-  ])
+  }, [contextMenu.isOpen, contextMenu.row, rowSelection, normalizedSelection, rows, displayColumns])
 
   const addToChat = useAddToChat()
   const handleAddSelectionToChat = useCallback(async () => {