Streaming Downloads: Export Large Files Without Crashing Memory

A common mistake is generating a large export fully in memory and then returning it. This can crash servers.

    Streaming sends data chunk by chunk.
    
    ## Stream a CSV response
    
    ```php
    return response()->streamDownload(function () {
      $handle = fopen('php://output', 'w');
      fputcsv($handle, ['id', 'name', 'email']);
    
      User::query()->chunk(1000, function ($users) use ($handle) {
        foreach ($users as $user) {
          fputcsv($handle, [$user->id, $user->name, $user->email]);
        }
      });
    
      fclose($handle);
    }, 'users.csv');
    ```
    
    ## Flow
    
    ```mermaid
    flowchart LR
      A[Request Export] --> B[Chunk Query]
      B --> C[Write Rows]
      C --> D[Stream to Client]
    ```
    
    In the next tutorial, we will implement advanced search filters with query builders.