Dragging the mouse near a field edge (Global Suche, the importer, etc.) started a text selection of the surrounding page titles/labels instead of feeling like an app. Disable user-select on the #app shell; re-enable it for real text fields (input/textarea/contenteditable) and copyable content (lyrics). Setup screen is outside #app and unaffected. SW cache -> ns-v66. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>