Batch process PDFs

Checks each file, rewrites its internal structure with qpdf, then checks again: rebuilds the cross-reference table, drops orphan objects and recompresses streams. Files qpdf can't parse are reported as failed. Good for a folder of files that won't open.

One text file per PDF, page by page. Scanned pages with no text layer come out empty.

Exports the images stored inside each PDF. JPEG comes out byte-for-byte; other formats are re-encoded as PNG. Each file gets its own folder in the ZIP, with a manifest.txt listing what was found.

Every page becomes an image; each file gets its own folder in the ZIP.