Please help me complete the query service business code for the `System Platform` object.

To ensure absolute correctness of the API, please refer to and strictly imitate the following **real code example for `System Platform`**.

### Standard Query Example (Reference)
Please carefully observe the `selectXxx()` methods and the strictly required `.purpose()` and `.comment()` cascade in the example code:

```java
import io.teaql.core.Context;
import com.yourcompany.domain.Q;
import com.yourcompany.domain.Platform;
import java.util.List;

public class PlatformQueryService {

    public List<Platform\> queryExample(Context ctx) {
        // [BEST PRACTICE]: Always start with WithMinimalFields() to avoid over-fetching
        var rows = Q.platformsWithMinimalFields()
            .selectName()
            .selectCreateTime()
            .selectLastUpdateTime()

            // --- Filter and Order Options (Uncomment and customize if needed) ---
            // .filterById(/* value */)
            // .orderByIdDescending() // or Ascending()
            // .filterByName(/* value */)
            // .orderByNameDescending() // or Ascending()
            // .filterByCreateTime(/* value */)
            // .orderByCreateTimeDescending() // or Ascending()
            // .filterByLastUpdateTime(/* value */)
            // .orderByLastUpdateTimeDescending() // or Ascending()
            // .filterByVersion(/* value */)
            // .orderByVersionDescending() // or Ascending()
            // --------------------------------------------------------------------

            // --- Advanced Options: Fetch nested objects and tailor fields (uncomment as needed) ---
            // .selectMerchantListWith(
            //     Q.merchantsWithMinimalFields()
            //         .selectName()
            //         .selectTaxNumber()
            //         .selectAddress()
            //         .selectExternalId()
            //         .selectPlatform()
            //         .selectCreateTime()
            //         .selectUpdateTime()
            // )
            // -----------------------------------------------------------------------------------------------

            .limit(20)
            // [CRITICAL]: All executeForList / execute must cascade these two methods!
            .comment("what: Please explain what this query loads here")
            .purpose("why: Please explain why this query is needed here")
            .executeForList(ctx);

        return rows;
    }
}
```

### Your Task
Please completely imitate the framework, imports, and syntax features of the above code to implement the real query logic for `System Platform` based on my specific business needs. Please output the Java source code directly.