[OCaml] Mobile-friendly clone of cgit.
style harmonize anchor elements with cgit-inspired pattern
Links appear as ordinary text (color:inherit, no decoration) by default. On hover they become blue (skyblue) + underlined, and the parent element (li, span, dd) receives a subtle #252525 background highlight to emphasize the interactive context. Commit list items are aligned with directory list items: the li uses align-items:stretch so child anchors fill the full row height, providing wide click targets. The commit-title anchor is now a flex item that stretches to fill available space. Pills have vertical margins so they don't dictate row height. The 'raw' link on file pages is now an ordinary anchor placed before the blob listing, no longer a button-styled toolbar element. Button-styled elements (nav items, pagination, toolbar buttons) retain their bespoke hover treatments and suppress the global blue+underline. Line-number anchors in the blob view keep their specialized behavior.