Fix dictionary type mismatch in columnar_to_row conversion

When an array is dictionary-encoded, store the actual array type instead
of the schema type in TypedArray::Dictionary. This fixes the error
"Expected Dictionary type but got Binary" that occurred when processing
BloomFilter columns with native_comet scan implementation.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: andygrove

native/core/src/execution/columnar_to_row.rs

@@ -78,7 +78,7 @@ enum TypedArray<'a> {
 
 impl<'a> TypedArray<'a> {
     /// Pre-downcast an ArrayRef to a TypedArray.
-    fn from_array(array: &'a ArrayRef, schema_type: &DataType) -> CometResult<Self> {
+    fn from_array(array: &'a ArrayRef, _schema_type: &DataType) -> CometResult<Self> {
         let actual_type = array.data_type();
         match actual_type {
             DataType::Boolean => Ok(TypedArray::Boolean(
@@ -223,7 +223,7 @@ impl<'a> TypedArray<'a> {
                 })?,
                 Arc::clone(field),
             )),
-            DataType::Dictionary(_, _) => Ok(TypedArray::Dictionary(array, schema_type.clone())),
+            DataType::Dictionary(_, _) => Ok(TypedArray::Dictionary(array, actual_type.clone())),
             _ => Err(CometError::Internal(format!(
                 "Unsupported data type for pre-downcast: {:?}",
                 actual_type