Fix UI inconsistencies across templates

- Replace .separator with .dropdown_separator in 4 dropdown menus
- Change gray-* to zinc-* color classes in online store templates
- Wrap hardcoded page titles in gettext() in online store templates
- Add consistent dark:text-zinc-200 to maintenance h3 subsections
- Add text-zinc-900 dark:text-zinc-200 to scrobble section headers
- Fix heading hierarchy (h1/h2 → h2/h3) in record set items
- Align artist form modal header to text-lg font-semibold
- Use size="xs" prop instead of class override on format badge
- Add external link icon to wishlist online store buttons

lib/music_library_web/live/artist_live/form.ex

@@ -20,7 +20,7 @@ defmodule MusicLibraryWeb.ArtistLive.Form do
     ~H"""
     <div class="w-full">
       <header>
-        <h1 class="text-base font-medium leading-6 text-zinc-700 dark:text-zinc-300">
+        <h1 class="text-lg font-semibold text-zinc-900 dark:text-zinc-100">
           {@artist.name}
         </h1>
       </header>