Chat sessions without a project were dropped from the mobile session tree
because no registered project owned their directory. The sheet now partitions
sessions like the desktop sidebar and shows Chats as a collapsible section above
the project tree, with the same rows, swipe actions and paging; search results
label them "Chats" instead of the raw directory name.
Claude-Session: https://claude.ai/code/session_017TK5JAYDfT3Fotc23UEg98