Please help me complete the delete (Soft Delete) service business code for the `System Platform` object.

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

### Standard Delete Example (Reference)
Please carefully observe the querying mechanism and the strictly required `.mark_as_delete()`, `.audit_as()`, and `.save()` cascade in the example code. 
**Note:** Data MUST NOT be deleted implicitly or physically. Unless `.mark_as_delete()` is explicitly called, no command should delete any data.

```rust
use teaql_core::Entity;
use crm_erp_service_core::{Q, System Platform, TeaqlRepositoryProvider, AuditedSave};

pub async fn delete_example(
    ctx: &impl TeaqlRepositoryProvider, 
    entity_id: i64
) -> Result<bool, Box<dyn std::error::Error>>
{
    // 1. Fetch the entity first (Use _minimal to avoid over-fetching during deletion checks)
    if let Some(mut existing_entity) = Q::platforms_minimal()
        .with_id_is(entity_id)
        .comment("what: Find entity for soft deletion")
        .purpose("why: Need to execute soft delete")
        .execute(ctx)
        .await?
    {
        // 2. CRITICAL: Execute mark_as_delete and attach security audit constraints before saving!
        existing_entity.mark_as_delete();
        existing_entity.audit_as("Why this soft delete operation was executed (audit record)")
            .save(ctx).await?;

        return Ok(true);
    }

    Ok(false)
}
```

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