Taskbar showed two icons because the AppUserModelID was (a) set too late — after the main window was built, so its taskbar button grouped under a mismatched implicit AUMID — and (b) valued 'LotusGuild.LotusChat', which differs from the bundle identifier 'org.lotusguild.lotus-chat' that Tauri's NSIS installer stamps on its shortcuts. Fix both: set the AUMID at the top of run() before the window is built (new set_process_aumid, split out of ensure_app_user_model_id), and align the constant to the bundle identifier so the running window and a pinned installer shortcut group together. Notification click didn't raise the window: add a focus_main_window command (reuses show_main) for the web/service-worker path, and call show_main directly in the rich-toast Activated body-click handler. Note: existing users who pinned the old mis-grouped icon may need to re-pin once. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>