improve email settings progressive enhancement and admin layout

- semantic HTML: step numbers inside h2, strong provider names, details
  for adapter configs, strong error messages, fieldset drawer toggle hidden
- inline field errors via flash for no-JS controller fallback
- single form POST button for test email (works with and without JS)
- admin sidebar: remove brand/view-shop, move user email to footer nav
- replace inline style with .admin-setup-step-spaced class
- clean up unused CSS (.admin-brand, .admin-sidebar-header, etc.)

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

lib/berrypod_web/live/admin/email_settings.ex

@@ -11,7 +11,11 @@ defmodule BerrypodWeb.Admin.EmailSettings do
     {current_adapter, _current_values} = Mailer.current_config()
     saved_adapter = Settings.get_setting("email_adapter")
 
-    adapter_key = current_adapter || saved_adapter
+    # Controller fallback passes errors via flash after failed validation
+    flash_adapter = Phoenix.Flash.get(socket.assigns.flash, :error_adapter)
+    flash_errors = Phoenix.Flash.get(socket.assigns.flash, :field_errors) || %{}
+
+    adapter_key = flash_adapter || current_adapter || saved_adapter
     grouped = Adapters.grouped()
     all_adapters = Adapters.all()
     all_values = load_all_adapter_values()
@@ -32,7 +36,7 @@ defmodule BerrypodWeb.Admin.EmailSettings do
      |> assign(:test_error, nil)
      |> assign(:test_retryable, false)
      |> assign(:from_checklist, false)
-     |> assign(:field_errors, %{})
+     |> assign(:field_errors, flash_errors)
      |> assign(:form, to_form(%{}, as: :email))}
   end
 
@@ -188,10 +192,9 @@ defmodule BerrypodWeb.Admin.EmailSettings do
         >
           <%!-- Step 1: Choose a provider --%>
           <div class="admin-setup-step">
-            <div class="admin-setup-step-header">
-              <span class="admin-setup-step-number">1</span>
-              <h2 class="admin-setup-step-title">Choose a provider</h2>
-            </div>
+            <h2 class="admin-setup-step-header">
+              <span class="admin-setup-step-number">1</span> Choose a provider
+            </h2>
 
             <fieldset class="card-radio-fieldset" disabled={@env_locked}>
               <legend class="sr-only">Email provider</legend>
@@ -205,7 +208,10 @@ defmodule BerrypodWeb.Admin.EmailSettings do
                 />
               </div>
 
-              <details class="admin-provider-other">
+              <details
+                class="admin-provider-other"
+                open={@adapter_key in Enum.map(@advanced_adapters, & &1.key)}
+              >
                 <summary class="admin-provider-other-toggle">
                   Already have your own email server?
                 </summary>
@@ -237,10 +243,9 @@ defmodule BerrypodWeb.Admin.EmailSettings do
       <div
         :if={@email_configured}
         id="test-email-step"
-        class="admin-setup-step"
-        style="margin-top: 1.5rem;"
+        class="admin-setup-step admin-setup-step-spaced"
       >
-        <div class="admin-setup-step-header">
+        <h2 class="admin-setup-step-header">
           <span class={[
             "admin-setup-step-number",
             @test_result == :ok && "admin-setup-step-number-done",
@@ -255,17 +260,15 @@ defmodule BerrypodWeb.Admin.EmailSettings do
                 {if @selected_adapter && @selected_adapter.url, do: "4", else: "3"}
             <% end %>
           </span>
-          <h2 class="admin-setup-step-title">
-            <%= cond do %>
-              <% @test_result == :ok -> %>
-                Email is working
-              <% @test_result == :error -> %>
-                Test failed
-              <% true -> %>
-                Send a test email
-            <% end %>
-          </h2>
-        </div>
+          <%= cond do %>
+            <% @test_result == :ok -> %>
+              Email is working
+            <% @test_result == :error -> %>
+              Test failed
+            <% true -> %>
+              Send a test email
+          <% end %>
+        </h2>
 
         <%= if @test_result == :ok do %>
           <p class="admin-setup-step-desc">
@@ -308,35 +311,17 @@ defmodule BerrypodWeb.Admin.EmailSettings do
             <p class="admin-setup-step-desc">
               Send a test to <strong>{@current_scope.user.email}</strong> to check everything works.
             </p>
-            <div class="admin-row admin-row-sm">
-              <%!-- JS: async send via LiveView --%>
-              <span id="test-email-js">
-                <.button
-                  type="button"
-                  phx-click="send_test"
-                  disabled={@sending_test}
-                  phx-disable-with="Sending..."
-                >
-                  <.icon name="hero-paper-airplane" class="size-4" /> Send test email
-                </.button>
-              </span>
-              <%!-- No-JS: form POST fallback (hides the JS button above) --%>
-              <noscript>
-                <style>
-                  #test-email-js { display: none; }
-                </style>
-                <.form
-                  for={%{}}
-                  action={~p"/admin/settings/email/test"}
-                  method="post"
-                  style="display:inline"
-                >
-                  <.button>
-                    <.icon name="hero-paper-airplane" class="size-4" /> Send test email
-                  </.button>
-                </.form>
-              </noscript>
-            </div>
+            <.form
+              for={%{}}
+              action={~p"/admin/settings/email/test"}
+              phx-submit="send_test"
+              method="post"
+              class="admin-row admin-row-sm"
+            >
+              <.button disabled={@sending_test} phx-disable-with="Sending...">
+                <.icon name="hero-paper-airplane" class="size-4" /> Send test email
+              </.button>
+            </.form>
           <% end %>
         <% end %>
       </div>
@@ -354,13 +339,13 @@ defmodule BerrypodWeb.Admin.EmailSettings do
 
   defp adapter_config(assigns) do
     ~H"""
-    <div hidden={!@selected} class="admin-adapter-config" data-adapter={@adapter.key}>
+    <details open={@selected} class="admin-adapter-config" data-adapter={@adapter.key}>
+      <summary class="admin-adapter-config-summary">Configure {@adapter.name}</summary>
       <%!-- Create an account (providers with sign-up URLs) --%>
       <div :if={@adapter.url} class="admin-setup-step">
-        <div class="admin-setup-step-header">
-          <span class="admin-setup-step-number">2</span>
-          <h2 class="admin-setup-step-title">Create a free account</h2>
-        </div>
+        <h2 class="admin-setup-step-header">
+          <span class="admin-setup-step-number">2</span> Create a free account
+        </h2>
         <p class="admin-setup-step-desc">
           <.external_link href={@adapter.url} class="admin-link">
             Sign up at {@adapter.name} &nearr;
@@ -371,12 +356,12 @@ defmodule BerrypodWeb.Admin.EmailSettings do
 
       <%!-- Paste your key / server details --%>
       <div class="admin-setup-step">
-        <div class="admin-setup-step-header">
+        <h2 class="admin-setup-step-header">
           <span class="admin-setup-step-number">
             {if @adapter.url, do: "3", else: "2"}
           </span>
-          <h2 class="admin-setup-step-title">{adapter_fields_title(@adapter)}</h2>
-        </div>
+          {adapter_fields_title(@adapter)}
+        </h2>
         <p class="admin-setup-step-desc">{adapter_fields_instruction(@adapter)}</p>
         <%= for field <- @adapter.fields do %>
           <.adapter_field_input
@@ -395,7 +380,7 @@ defmodule BerrypodWeb.Admin.EmailSettings do
           </div>
         <% end %>
       </div>
-    </div>
+    </details>
     """
   end
 
@@ -435,12 +420,12 @@ defmodule BerrypodWeb.Admin.EmailSettings do
         disabled={@disabled}
         class="card-radio-input"
       />
-      <div class="card-radio-name">
-        {@adapter.name}
+      <span class="card-radio-name">
+        <strong>{@adapter.name}</strong>
         <span :if={@adapter.recommended} class="card-radio-badge card-radio-recommended">
           Recommended
         </span>
-      </div>
+      </span>
       <div :if={@adapter.free_tier} class="card-radio-description">{@adapter.free_tier}</div>
       <div :if={@adapter.setup_hint} class="card-radio-description">{@adapter.setup_hint}</div>
     </label>