Escape special characters (&, <, >, ", ') in the title attribute of TextThreadContext's XML output to prevent malformed XML when titles contain these characters. Resolves TODO at context.rs:629 Release Notes: - N/A Signed-off-by: Xiaobo Liu <cppcoffee@gmail.com> Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>