fonts: consolidate font-family to global stack, self-host subset emoji font

Remove redundant `font-family: sans-serif` from 18 component-level
declarations — they now inherit the Helvetica/Arial/Noto Sans stack
from the global `*` selector in app.css.

Add self-hosted NotoColorEmoji subset (56 KB, down from 11 MB) as
fallback for systems without the Noto Color Emoji font installed.
The subset is generated at prebuild time via pyftsubset with a fixed
list of the ~32 emojis actually used on the site.

src/lib/components/recipes/IngredientsPage.svelte

@@ -308,9 +308,6 @@ function adjust_amount(string, multiplier){
 // No need for complex yeast toggle handling - everything is calculated server-side now
 </script>
 <style>
-*{
-font-family: sans-serif;
-}
 .ingredients{
 	flex-basis: 0;
 	flex-grow: 1;