restore browser video codec defaults

public/index.html

@@ -150,6 +150,14 @@
     </div>
     <p id="mic-clipping" class="hint hidden">Clipping detected — reduce microphone gain.</p>
     <p class="hint">Changes apply immediately when connected, or the next time you join.</p>
+    <h3>Screen sharing</h3>
+    <label class="field-label" for="screen-hint">Optimization</label>
+    <select id="screen-hint" class="settings-select">
+      <option value="">Browser default</option>
+      <option value="detail">Details / text editor / terminal</option>
+      <option value="motion">Gameplay / motion</option>
+    </select>
+    <p class="hint">Details favors sharp text; motion favors smoother movement.</p>
     <p class="hint">Overrides the server-provided ICE configuration (stored in <code>localStorage</code>, applied on next join).</p>
     <label class="toggle-row">
       <input type="checkbox" id="override-enabled" />