Add chapter images: thumbnail on the list, headline image on the detail page

_chapter.html.erb (the aggregator partial used by the erfas/
chaostreffs overview pages) never rendered an image at all --
editors attaching a hackerspace photo via the asset picker would see
zero visible effect on exactly the pages they'd check first.
chapter_detail.html.erb (the individual page template) had the same
gap. Both fixed by reusing existing infrastructure rather than
inventing anything: the overview list gets a small, aspect-preserving
:thumb image beside the heading; the detail page gets the app's
existing headline_image helper, the same one every other full-page
template already uses.

3 files changed, 40 insertions, 15 deletions

diff --git a/app/views/custom/page_templates/public/chapter_detail.html.erb b/app/views/custom/page_templates/public/chapter_detail.html.erb
index f47353c..c4c2598 100644
--- a/app/views/custom/page_templates/public/chapter_detail.html.erb
+++ b/app/views/custom/page_templates/public/chapter_detail.html.erb
@@ -1,5 +1,6 @@
 <div class="article" lang="<%= @page.effective_lang %>">
   <h2 class="headline"><%= @page.title %></h2>
+  <%= headline_image %>
   <% if @page.node.external_url.present? %>
     <div class="chapter_url"><%= link_to @page.node.external_url, @page.node.external_url, target: '_blank', rel: 'noopener' %></div>
   <% end %>
diff --git a/app/views/custom/partials/_chapter.html.erb b/app/views/custom/partials/_chapter.html.erb
index 805559b..47f3950 100644
--- a/app/views/custom/partials/_chapter.html.erb
+++ b/app/views/custom/partials/_chapter.html.erb
@@ -1,19 +1,26 @@
 <div class="article_partial chapter_partial" lang="<%= page.effective_lang %>">
-  <h2 class="headline"><%= link_to_path page.title, page.node.unique_name %></h2>
-  <% if page.abstract.present? %>
-    <div class="chapter_location"><%= page.abstract %></div>
-  <% end %>
-  <% if page.node.external_url.present? %>
-    <div class="chapter_url"><%= link_to page.node.external_url, page.node.external_url, target: '_blank', rel: 'noopener' %></div>
-  <% end %>
-  <% open_days = page.node.events.tagged_with('open-day').order(:start_time) %>
-  <% if open_days.any? %>
-    <div class="chapter_open_days">
-      <span class="open_days_label"><%= t(:open_days_label) %>: </span>
-      <% open_days.each do |event| %>
-        <span class="event_schedule"><%= event_schedule_text(event) %></span>
+  <div class="chapter_partial_layout">
+    <% if page.assets.images.any? %>
+      <%= link_to_path image_tag(page.assets.images.first.upload.url(:thumb), :alt => ""), page.node.unique_name, class: "chapter_thumbnail" %>
+    <% end %>
+    <div class="chapter_partial_content">
+      <h2 class="headline"><%= link_to_path page.title, page.node.unique_name %></h2>
+      <% if page.abstract.present? %>
+        <div class="chapter_location"><%= page.abstract %></div>
       <% end %>
+      <% if page.node.external_url.present? %>
+        <div class="chapter_url"><%= link_to page.node.external_url, page.node.external_url, target: '_blank', rel: 'noopener' %></div>
+      <% end %>
+      <% open_days = page.node.events.tagged_with('open-day').order(:start_time) %>
+      <% if open_days.any? %>
+        <div class="chapter_open_days">
+          <span class="open_days_label"><%= t(:open_days_label) %>: </span>
+          <% open_days.each do |event| %>
+            <span class="event_schedule"><%= event_schedule_text(event) %></span>
+          <% end %>
+        </div>
+      <% end %>
+      <p class="excerpt"><%= sanitize page.body %></p>
     </div>
-  <% end %>
-  <p class="excerpt"><%= sanitize page.body %></p>
+  </div>
 </div>
diff --git a/public/stylesheets/ccc.css b/public/stylesheets/ccc.css
index fe2144f..bb4f7e3 100644
--- a/public/stylesheets/ccc.css
+++ b/public/stylesheets/ccc.css
@@ -610,3 +610,20 @@ label[for=light-mode] {
   }
 }
 
+.chapter_partial_layout {
+  display: flex;
+  gap: 12px;
+  align-items: flex-start;
+}
+
+.chapter_thumbnail img {
+  width: 64px;
+  height: 64px;
+  object-fit: cover;
+  border-radius: 4px;
+  display: block;
+}
+
+.chapter_partial_content {
+  min-width: 0;
+}