PDF Case: Progress Note Preview

Reproduces the Aarista/charta progress-note flow: a PDF is fetched over the network, wrapped in a blob: URL, and shown inside a "Progress Note Preview" modal iframe (title="progress_note_pdf", src="blob:…#toolbar=0"). On a worker with --disable-pdf-viewer the iframe renders Chrome's dead download stub instead of the PDF, so the download the FILE_DOWNLOAD node waits for never fires (DOWNLOAD-E0001). Use the modal buttons to test capture strategies.