complete admin CSS refactor: delete utilities.css, add layout primitives

- Delete utilities.css (701 lines / 24 KB of Tailwind utility clones)
- Add layout.css with admin-stack, admin-row, admin-cluster, admin-grid
  primitives and gap variants (sm, md, lg, xl)
- Add transitions.css import and layout.css import to admin.css entry point
- Replace all Tailwind utility classes across 26 admin templates with
  semantic admin-*/theme-*/page-specific CSS classes
- Replace all non-dynamic inline styles with semantic classes
- Add ~100 new semantic classes to components.css (analytics, dashboard,
  order detail, settings, theme editor, generic utilities)
- Fix stray text-error → admin-text-error in media.ex
- Add missing .truncate definition to admin CSS
- Only remaining inline styles are dynamic data values (progress bars,
  chart dimensions) and one JS.toggle target

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/berrypod_web/components/core_components.ex

@@ -62,8 +62,8 @@ defmodule BerrypodWeb.CoreComponents do
           <p>{msg}</p>
         </div>
         <div class="admin-alert-spacer" />
-        <button type="button" class="group self-start cursor-pointer" aria-label={gettext("close")}>
-          <.icon name="hero-x-mark" class="size-5 opacity-40 group-hover:opacity-70" />
+        <button type="button" class="admin-alert-close" aria-label={gettext("close")}>
+          <.icon name="hero-x-mark" class="size-5" />
         </button>
       </div>
     </div>
@@ -351,7 +351,7 @@ defmodule BerrypodWeb.CoreComponents do
             <td
               :for={col <- @col}
               phx-click={@row_click && @row_click.(row)}
-              class={@row_click && "hover:cursor-pointer"}
+              class={@row_click && "admin-table-row-clickable"}
             >
               {render_slot(col, @row_item.(row))}
             </td>