feat(api): add columnsScope() alias replacing deprecated properties()

 A new alias function `columnsScope()` was introduced for column-accessor-only completion. The original `properties()` function was deprecated with a ReplaceWith suggestion to maintain compatibility. KDoc and source updates were added to clarify usage and avoid breaking changes.

Author: jetbrains-junie[bot]

core/generated-sources/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/DataFrameGet.kt

@@ -82,8 +82,19 @@ public fun <T> ColumnsContainer<T>.getColumnGroup(columnPath: ColumnPath): Colum
  * df.properties().
  * ```
  */
+@Deprecated("Renamed for clarity: use columnsScope() to access generated column properties only", ReplaceWith("columnsScope()"))
 public fun <T> DataFrame<T>.properties(): ColumnsScope<T> = this
 
+/**
+ * Returns a ColumnsScope that exposes only generated column accessor properties for code completion,
+ * hiding the rest of the DataFrame API. Useful to quickly discover available columns.
+ *
+ * Example:
+ * val df = DataFrame.read("file.csv")
+ * df.columnsScope(). // shows only column accessors in auto-complete
+ */
+public fun <T> DataFrame<T>.columnsScope(): ColumnsScope<T> = this
+
 // region getColumn
 
 public fun <T> ColumnsContainer<T>.getColumn(name: String): AnyCol =

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/api/DataFrameGet.kt

@@ -82,8 +82,19 @@ public fun <T> ColumnsContainer<T>.getColumnGroup(columnPath: ColumnPath): Colum
  * df.properties().
  * ```
  */
+@Deprecated("Renamed for clarity: use columnsScope() to access generated column properties only", ReplaceWith("columnsScope()"))
 public fun <T> DataFrame<T>.properties(): ColumnsScope<T> = this
 
+/**
+ * Returns a ColumnsScope that exposes only generated column accessor properties for code completion,
+ * hiding the rest of the DataFrame API. Useful to quickly discover available columns.
+ *
+ * Example:
+ * val df = DataFrame.read("file.csv")
+ * df.columnsScope(). // shows only column accessors in auto-complete
+ */
+public fun <T> DataFrame<T>.columnsScope(): ColumnsScope<T> = this
+
 // region getColumn
 
 public fun <T> ColumnsContainer<T>.getColumn(name: String): AnyCol =