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

test/music_library_web/live/record_set_live/show_test.exs

@@ -28,8 +28,8 @@ defmodule MusicLibraryWeb.RecordSetLive.ShowTest do
 
       conn
       |> visit(~p"/record-sets/#{set}")
-      |> assert_has("h2", escape(r1.title))
-      |> assert_has("h2", escape(r2.title))
+      |> assert_has("h3", escape(r1.title))
+      |> assert_has("h3", escape(r2.title))
     end
 
     test "shows add record tile when set has no records", %{conn: conn} do