Fix black chat pane and restore jumbo emoji rendering.

Column flex on keep-alive room hosts so the timeline fills the pane again, and route unicode jumbo through the plain emoji path with dedicated HTML parser options for custom emoticons.

src/app/features/room/ThreadView.tsx

@@ -212,6 +212,17 @@ export function ThreadView({ room, threadRootId }: ThreadViewProps) {
       }),
     [mx, room, linkifyOpts, spoilerClickHandler, mentionClickHandler, useAuthentication]
   );
+  const jumboHtmlReactParserOptions = useMemo<HTMLReactParserOptions>(
+    () =>
+      getReactCustomHtmlParser(mx, room.roomId, {
+        linkifyOpts,
+        useAuthentication,
+        handleSpoilerClick: spoilerClickHandler,
+        handleMentionClick: mentionClickHandler,
+        jumbo: true,
+      }),
+    [mx, room, linkifyOpts, spoilerClickHandler, mentionClickHandler, useAuthentication]
+  );
 
   const thread = room.getThread(threadRootId);
   const roomTimelineSet = room.getUnfilteredTimelineSet();
@@ -634,6 +645,7 @@ export function ThreadView({ room, threadRootId }: ThreadViewProps) {
                 mediaAutoLoad={mediaAutoLoad}
                 urlPreview={showUrlPreview}
                 htmlReactParserOptions={htmlReactParserOptions}
+                jumboHtmlReactParserOptions={jumboHtmlReactParserOptions}
                 linkifyOpts={linkifyOpts}
                 outlineAttachment={messageLayout === MessageLayout.Bubble}
                 disabledEmbedPatterns={combinedEmbedFilters}
@@ -650,6 +662,7 @@ export function ThreadView({ room, threadRootId }: ThreadViewProps) {
             mediaAutoLoad={mediaAutoLoad}
             urlPreview={showUrlPreview}
             htmlReactParserOptions={htmlReactParserOptions}
+            jumboHtmlReactParserOptions={jumboHtmlReactParserOptions}
             linkifyOpts={linkifyOpts}
             outlineAttachment={messageLayout === MessageLayout.Bubble}
             disabledEmbedPatterns={combinedEmbedFilters}