v0.5.4

• Fixed: two more lines of engine output reached the terminal on Linux.
  0.5.3 silenced the Python logging, which is all that macOS produces. A first
  run on Linux still showed onnxruntime announcing its PCI bus scan, and — while
  the model cache was still cold — a warning from the HuggingFace Hub about
  unauthenticated requests.

  The Hub one is a logger and simply joins the list. onnxruntime's could not be
  fixed that way: it is C++ writing straight to file descriptor 2, and the
  message is emitted while the module is importing, which defeats importing it
  early to lower its log severity. That import now runs with the file descriptor
  detached — only the import, so everything the conversion does afterwards keeps
  a live stderr and real failures still surface.

• Internal: tests/integration now runs in CI. It never had, because the normal
  test job installs only the markitdown extra — which is how 0.5.2 shipped a
  progress indicator buried under 107 lines of engine logging with every test
  passing. There is also a new scanned.pdf fixture of rasterised text, so
  docling's OCR path is exercised; every previous PDF fixture was born-digital
  and skipped it entirely.