Rename and consolidate portable user-data to usr/user-data and update tooling and runtime to match. Updated appdir-example/run-nebula.sh to point at usr/user-data; make-appdir.sh and update-appdir.sh now patch/copy the launcher, create the usr/user-data directory and set secure permissions (mkdir -p, chmod 700), and remove sed backups. portable-data.js now defaults to app-local user-data and prefers <AppDir>/usr/user-data on Linux AppDir builds (with safe fs checks). Also minor UI change in renderer/setup.css to make the footer background transparent and disable the backdrop blur.
andrew