feat: add intermission section separate from live games

Games in intermission now appear in their own section between Live and
Scheduled. The section is hidden when no games are in intermission,
matching the behavior of the other section headings.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/templates/index.html

@@ -21,6 +21,10 @@
             <h2 class="section-heading">Live</h2>
             <div id="live-games-section" class="games-grid"></div>
         </section>
+        <section id="intermission-section" class="section hidden">
+            <h2 class="section-heading">Intermission</h2>
+            <div id="intermission-games-section" class="games-grid"></div>
+        </section>
         <section id="pre-section" class="section hidden">
             <h2 class="section-heading">Scheduled</h2>
             <div id="pre-games-section" class="games-grid"></div>