Incorrect Preview Title and Download Message for HTML Conversion

Description: When converting a USFM file to HTML format, the preview page incorrectly displays the title as "PDF Preview." Additionally, when downloading files, both HTML and PDF downloads show the same message: "PDF download complete," even for HTML files.

Steps to Reproduce:

Upload a valid USFM file
Convert the file to HTML format
Check the preview page title
Download the HTML file
Observe the download message

Expected Result:

Preview page should display "HTML Preview" when HTML format is selected Download message should correctly reflect the file type (HTML or PDF)

Actual Result:

Preview page shows "PDF Preview" for HTML format Download message shows "PDF download complete" for both HTML and PDF files