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/routes/[recipeLang=recipeLang]/[name]/+page.svelte

@@ -106,9 +106,6 @@
 	});
 </script>
 <style>
-*{
-font-family: sans-serif;
-}
 h1{
 	text-align: center;
 	padding-block: 0.5em;

src/routes/[recipeLang=recipeLang]/icon/+page.svelte

@@ -14,7 +14,7 @@
 </svelte:head>
 <style>
 	a{
-		font-family: "Noto Color Emoji", emoji, sans-serif;
+		font-family: "Noto Color Emoji", "Noto Color Emoji Subset", emoji, sans-serif;
 		--padding: 0.5em;
 		font-size: 3rem;
 		text-decoration: none;