# Issue #011: Downloads Handling

**Tipo**: Enhancement
**Prioridad**: Media
**Estado**: Pendiente

## Descripción

Implementar sistema para detectar, gestionar y esperar downloads de archivos.

## Funcionalidad deseada

- Detectar cuando inicia un download
- Esperar a que download complete
- Obtener path del archivo descargado
- Configurar directorio de descargas
- Cancelar downloads en progreso
- Obtener progreso de download
- Manejar múltiples downloads simultáneos

## API propuesta

```go
type Download struct {
    ID       string
    URL      string
    Filename string
    Path     string
    MimeType string
    Size     int64
    State    DownloadState // "inProgress" | "completed" | "cancelled"
}

type DownloadState string
const (
    DownloadStateInProgress DownloadState = "inProgress"
    DownloadStateCompleted  DownloadState = "completed"
    DownloadStateCancelled  DownloadState = "cancelled"
)

type DownloadOptions struct {
    DownloadPath string // Directorio donde guardar
    Behavior     string // "allow" | "deny" | "allowAndName"
}

func (b *Browser) SetDownloadBehavior(ctx context.Context, opts *DownloadOptions) error
func (b *Browser) WaitForDownload(ctx context.Context, action func()) (*Download, error)
func (b *Browser) OnDownload(handler func(*Download)) error
func (b *Browser) GetDownloads(ctx context.Context) ([]*Download, error)
func (b *Browser) CancelDownload(ctx context.Context, downloadID string) error
```

## Uso

```go
// Configurar directorio de descargas
b.SetDownloadBehavior(ctx, &browser.DownloadOptions{
    DownloadPath: "/tmp/downloads",
    Behavior: "allow",
})

// Esperar download
download, _ := b.WaitForDownload(ctx, func() {
    b.Click(ctx, "#download-button")
})

log.Printf("Downloaded: %s to %s", download.Filename, download.Path)

// Handler de downloads
b.OnDownload(func(d *browser.Download) {
    log.Printf("Download started: %s", d.Filename)
})
```

## CDP Methods

- `Browser.setDownloadBehavior`
- `Page.downloadWillBegin` (evento)
- `Page.downloadProgress` (evento)

## Referencias

- CDP Browser.setDownloadBehavior: https://chromedevtools.github.io/devtools-protocol/tot/Browser/#method-setDownloadBehavior
- Playwright downloads: https://playwright.dev/docs/downloads