Add hidden model input for single model case

- When only 1 video-capable model exists, include hidden input field
- Form still submits the correct model_path value
- Maintains proper form functionality while hiding UI when not needed

templates/analyze.html

@@ -242,6 +242,8 @@
                     {% endfor %}
                 </select>
             </div>
+            {% elif video_models and video_models|length == 1 %}
+            <input type="hidden" name="model_path" value="{{ video_models[0].path }}">
             {% endif %}
 
             <div class="form-group">