pdf.js 6 removed PDFDocumentProxy.destroy(), so the PdfReader teardown threw
"destroy is not a function" on every unmount, breaking the client-side
navigation back to the book page (and sometimes showing the error page).
Close the document through its loading task instead (closePdf), which also
cancels a load still in flight. Test covers the pdf.js API and closePdf.
- Zoom buttons + Ctrl/Cmd +/-/0, Ctrl+wheel/trackpad pinch, touch pinch on PDFs;
PDF scales the pdf.js render (sharp re-render after it settles), EPUB scales text.
Remembered per format, and per book.
- One/two pages side by side: PDF rows with the cover alone, foliate max-column-count.
- Scroll vs Pages mode for both engines; PDF paged shows one page/spread fitted to the
screen, prev/next move a whole spread; spreads stack when scrolling.
- Reading position is kept across zoom/spread/mode changes; progress keeps saving.
- layout.ts helpers with unit tests; old flow/fontSize/pdfZoom settings migrate.
The Docker build runs vitest via bun (no Node in oven/bun), where the named
`{ z }` import from zod 4 resolved to undefined; the rest of the repo already
uses `import * as z from 'zod'`.
