Add folder icon to directory page H1 headings

Display a folder icon next to the H1 heading on directory listing pages
(like /photography) that don't have an index.md file. The icon is
generated based on the directory title with a unique color.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

tuftecms/blueprints/content.py

@@ -449,6 +449,10 @@ def serve_content(path):
             # Get title from directory name
             title = path.split("/")[-1].replace("-", " ").replace("_", " ").title()
 
+            # Generate folder icon for this directory
+            from ..utils.content import generate_folder_icon
+            folder_icon = generate_folder_icon(title, size=32)
+
             return render_template(
                 "directory.html",
                 items=items,
@@ -458,6 +462,7 @@ def serve_content(path):
                 title=title,
                 is_image_gallery=is_image_gallery,
                 image_items=image_items,
+                folder_icon=folder_icon,
             )
 
     # Handle markdown files

tuftecms/templates/directory.html

@@ -381,12 +381,34 @@ body.dark-mode .parent-link:hover {
         color: #ccc;
     }
 }
+
+/* Directory title icon */
+.directory-title-icon {
+    width: 32px;
+    height: 32px;
+    margin-right: 0.5rem;
+    vertical-align: middle;
+    display: inline-block;
+}
+
+@media (max-width: 760px) {
+    .directory-title-icon {
+        width: 24px;
+        height: 24px;
+        margin-right: 0.4rem;
+    }
+}
 </style>
 {% endblock %}
 
 {% block content %}
 {% if current_path and current_path != '' %}
-    <h1>{{ current_path.split('/')[-1] if '/' in current_path else current_path }}</h1>
+    <h1>
+        {% if folder_icon %}
+        <img src="{{ folder_icon }}" alt="Folder icon" class="directory-title-icon">
+        {% endif %}
+        {{ current_path.split('/')[-1] if '/' in current_path else current_path }}
+    </h1>
 {% endif %}
 
 {% if index_content and content_position == 'top' %}