Expanded dashboard fonts with preview picker
- The dashboard font setting now offers 30 more fonts (15 sans-serif and 15 serif) alongside the existing six and Theme default. Your saved choices still work.
- The font menu shows each option in its own typeface, grouped under clear category headings. You can navigate it with the keyboard and type to search. Preview fonts only download when they scroll into view, and nothing is preloaded.
- All new fonts are SIL OFL 1.1 Latin subsets, and each one's license and source details are bundled with it. Fonts whose license reserves the original name use neutral names (e.g. "Dreb Serif 02") with a "Based on …" line underneath.
- The dashboard docs now explain how to set up custom fonts.
Contributed by @Anjiro81 in PR 540, resolving issue 510.