9efa052b6d
Bite-sized implementation plan for spec 0002 (case-page half of #14): add a gated "Kopieren + Schließen" control below the document (Task 1, with a shared copyDocText() refactor), a bare "Schließen" for documentless open cases (Task 2), then remove the H1 trash-can close (Task 3), and a whole-suite + clippy + fmt gate (Task 4). Ordered so each task leaves the suite green. refs #14