Implement image upload functionality with metadata storage; update frontend to display uploaded images

Co-authored-by: Copilot <copilot@github.com>

frontend/app/templates/dashboard.html

@@ -5,4 +5,24 @@ endblock %} {% block content %}
   <p>Role: <strong>{{ user.get('role', 'user') }}</strong></p>
   <a href="{{ url_for('generate') }}" class="btn">Start generating</a>
 </div>
-{% endblock %}
+
+{% if images %}
+<div class="card mt-2">
+  <h2>Uploaded reference images</h2>
+  <div class="image-grid">
+    {% for img in images %}
+    <div class="image-grid-item">
+      <img
+        src="{{ url_for('serve_uploaded_image', image_id=img.id) }}"
+        alt="{{ img.filename }}"
+        class="generated-image"
+        loading="lazy"
+      />
+      <p class="text-muted" style="font-size: 0.75rem; margin-top: 0.25rem">
+        {{ img.filename }} &mdash; {{ (img.size_bytes / 1024) | round(1) }} KB
+      </p>
+    </div>
+    {% endfor %}
+  </div>
+</div>
+{% endif %} {% endblock %}