Add Shared Media drawer and harden same-room navigation.

Widen the media panel, support skinny full-page mode, keep jump-to-latest and return-to-previous reliable, and stop same-room event jumps from remounting the outlet or yanking the sidebar.

src/app/features/search/Search.tsx

@@ -145,11 +145,23 @@ export function Search({ requestClose }: SearchProps) {
 
   const getTargetStr: SearchItemStrGetter<string> = useCallback(
     (roomId: string) => {
-      const roomName = getRoom(roomId)?.name ?? roomId;
+      const room = getRoom(roomId);
+      const roomName = room?.name ?? roomId;
       if (mDirects.has(roomId)) {
         const targetUserId = getDmUserId(roomId, getRoom, mx.getSafeUserId());
-        const targetUsername = targetUserId && getMxIdLocalPart(targetUserId);
-        if (targetUsername) return [roomName, targetUsername];
+        if (!targetUserId) return roomName;
+        const targetUsername = getMxIdLocalPart(targetUserId);
+        const targetServer = getMxIdServer(targetUserId);
+        const member = room?.getMember(targetUserId);
+        const displayName = member?.name || member?.rawDisplayName;
+        return [
+          roomName,
+          displayName,
+          targetUsername,
+          targetUserId,
+          targetServer ? `@${targetUsername}:${targetServer}` : undefined,
+          targetServer,
+        ].filter((s): s is string => typeof s === 'string' && s.length > 0);
       }
       return roomName;
     },