Incorrect query results

[TA-5]

**Describe the bug**

When using `withIndex()` in combination with `limit()`, the package incorrectly generates a DynamoDB `Scan` 
operation instead of a `Query` operation. 

This results in:

1. Performance Issues: Scanning the entire GSI instead of querying it efficiently
2. Incorrect Results: Returns 0 results when it should return the limited number of items  
3. Wrong Operation Type: Uses `FilterExpression` (Scan) instead of `KeyConditionExpression` (Query)

The bug occurs specifically when chaining `withIndex()`, `where()`, and `limit()` together. Without `limit()`, 
the query works correctly and uses the proper Query operation.

**Schema**

Table schema:
* Primary key: Composite key `PK` (partition key), `SK` (sort key)
* GSI1: `TasksByStatusIndex`
  - Partition key: `GSI1PK` (e.g., "STATUS#OPEN")
  - Sort key: `GSI1SK` (e.g., "T")
* GSI2: `TasksByUserIndex`
  - Partition key: `GSI2PK` (e.g., "USER#123") 
  - Sort key: `GSI2SK` (e.g., "OPEN#T")

Model configuration:
```php
public function getDynamoDbIndexKeys() {
    return [
        'TasksByStatusIndex' => [
            'hash' => 'GSI1PK',
            'range' => 'GSI1SK',
        ],
        'TasksByUserIndex' => [
            'hash' => 'GSI2PK',
            'range' => 'GSI2SK',
        ],
    ];
}

Debug info

Working query (without limit):

$query = Task::withIndex('TasksByStatusIndex')->where('GSI1PK', 'STATUS#OPEN');
print_r($query->toDynamoDbQuery());

Results in proper Query operation (works correctly, returns 17 results).

Broken query (with limit):

$query = Task::withIndex('TasksByStatusIndex')->where('GSI1PK', 'STATUS#OPEN')->limit(2);
print_r($query->toDynamoDbQuery());

Output:

BaoPham\DynamoDb\RawDynamoDbQuery Object
(
    [op] => Scan        // ❌ Should be "Query"
    [query] => Array
        (
            [TableName] => local_tasks
            [FilterExpression] => #GSI1PK = :a1    // ❌ Should be "KeyConditionExpression"
            [IndexName] => TasksByStatusIndex
            [ExpressionAttributeNames] => Array
                (
                    [#GSI1PK] => GSI1PK
                )
            [ExpressionAttributeValues] => Array
                (
                    [:a1] => Array
                        (
                            [S] => STATUS#OPEN
                        )
                )
        )
)

Expected behavior: Should generate a Query operation with KeyConditionExpression and return 2 results.
Actual behavior: Generates a Scan operation with FilterExpression and returns 0 results.

Reproduction steps:

1. Create a model extending DynamoDbModel with GSI configuration
2. Use Model::withIndex('IndexName')->where('GSI_KEY', 'value')->limit(N)->get()
3. Observe that it returns 0 results and uses Scan instead of Query

Workaround:
Use the raw DynamoDB client directly:

$client->query([
    'TableName' => $tableName,
    'IndexName' => 'TasksByStatusIndex',
    'KeyConditionExpression' => 'GSI1PK = :status', 
    'ExpressionAttributeValues' => [':status' => ['S' => 'STATUS#OPEN']],
    'Limit' => 2
]);

Version info

• Laravel: 12.20.0
• PHP: 8.3.0
• baopham/dynamodb: 6.6.0

Edit: better formatting of the report.