add logo to newsletter email header

Uses the shop logo image if configured, falls back to the favicon
icon (served as PNG) alongside the shop name, or plain text if
neither is available.

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

lib/berrypod/newsletter/notifier.ex

@@ -121,9 +121,10 @@ defmodule Berrypod.Newsletter.Notifier do
   end
 
   # Wraps HTML content in a branded email template.
-  # Keeps it simple: single column, shop name header, optional unsubscribe footer.
+  # Keeps it simple: single column, logo/shop name header, optional unsubscribe footer.
   @doc false
   def wrap_html(shop_name, content, unsubscribe_url \\ nil) do
+    logo_html = build_logo_html(shop_name)
     footer =
       if unsubscribe_url do
         """
@@ -167,7 +168,7 @@ defmodule Berrypod.Newsletter.Notifier do
             <table role="presentation" class="email-container" width="560" cellpadding="0" cellspacing="0" style="max-width: 560px; width: 100%; background-color: #ffffff; border-radius: 8px;">
               <tr>
                 <td class="email-header" style="padding: 24px 32px 16px; border-bottom: 1px solid #e5e7eb;">
-                  <strong style="font-size: 18px; color: #111827;">#{esc(shop_name)}</strong>
+                  #{logo_html}
                 </td>
               </tr>
               <tr>
@@ -186,6 +187,45 @@ defmodule Berrypod.Newsletter.Notifier do
     """
   end
 
+  # Builds the header logo/name HTML. Uses the shop logo if configured,
+  # falls back to the favicon (served as PNG), or plain text.
+  defp build_logo_html(shop_name) do
+    base_url = BerrypodWeb.Endpoint.url()
+    theme = Berrypod.Settings.get_theme_settings()
+
+    cond do
+      # Logo image configured and not SVG (email clients don't support SVG)
+      theme.logo_image_id && !is_svg_image?(theme.logo_image_id) ->
+        src = "#{base_url}/image_cache/#{theme.logo_image_id}.webp"
+        height = theme.logo_size || 36
+
+        ~s(<img src="#{esc(src)}" alt="#{esc(shop_name)}" height="#{height}" style="height: #{height}px; width: auto; display: block;">)
+
+      # Favicon icon exists (served as PNG at /apple-touch-icon.png)
+      has_favicon_icon?() ->
+        src = "#{base_url}/apple-touch-icon.png"
+
+        ~s(<img src="#{esc(src)}" alt="#{esc(shop_name)}" width="36" height="36" style="height: 36px; width: 36px; display: inline-block; vertical-align: middle; border-radius: 4px; margin-right: 8px;">) <>
+          ~s(<strong style="font-size: 18px; color: #111827; vertical-align: middle;">#{esc(shop_name)}</strong>)
+
+      # No image — text only
+      true ->
+        ~s(<strong style="font-size: 18px; color: #111827;">#{esc(shop_name)}</strong>)
+    end
+  end
+
+  defp is_svg_image?(image_id) do
+    case Berrypod.Repo.get(Berrypod.Media.Image, image_id) do
+      %{is_svg: true} -> true
+      _ -> false
+    end
+  end
+
+  defp has_favicon_icon? do
+    require Ecto.Query
+    Berrypod.Repo.exists?(Ecto.Query.from(i in Berrypod.Media.Image, where: i.image_type == "icon"))
+  end
+
   # Turns bare URLs in escaped text into clickable links.
   defp linkify(escaped_text) do
     Regex.replace(~r/(https?:\/\/[^\s<]+)/, escaped_text, fn url, _ ->