remove wrapup video rendering (ffmpeg)

SPA handles wrapup visuals client-side; server-side
renderer was dead code pulling in ffmpeg + image crates.

crates/adapters/template-askama/templates/wrapup.html

@@ -10,9 +10,6 @@
     {% if report.total_watch_time_minutes > 0 %}
     <div class="wu-detail">{{ watch_time_display }} of watch time</div>
     {% endif %}
-    {% if let Some(url) = video_url %}
-    <a href="{{ url }}" class="wu-video-link" download>Download Video</a>
-    {% endif %}
   </section>
 
   <section class="wu-section">