Replace the multi-line "Download docs" block with a compact single line
"Downloads: PDF | HTML | ePub" placed right below the search box.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Enable the pdf format on Read the Docs (the LaTeX build config already
existed in conf.py) and add a "Download docs" section to the sidebar that
links the offline formats (PDF, HTML zip, ...). The links are populated
from the Read the Docs addons data, reusing the same mechanism as the
version selector, so they are version-correct and hidden when unavailable.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
