Open a GUI PDF viewer (zathura) from an agent Bash tool without it dying or blocking

Launching zathura file.pdf & from an agent's Bash tool can block the call or get killed when the shell exits. Detach it fully: (setsid zathura path/to/file.pdf >/dev/null 2>&1 &), then confirm with pgrep -a zathura. Use a path relative to a cd'd directory or an absolute path. If the file is renamed later, the open window keeps the old path and its auto-reload breaks, so reopen it by the new name. Tell the user the plain command too (zathura file.pdf &) so they can open the next one themselves.