v0.20.11

Fixed

• PWA: Modal header stays visible while scrolling (closes #50)
  When creating or editing a task / calendar event on iOS PWA, the modal header (title + close button) no longer scrolls out of view when the form is long.
  Root cause: position: sticky failed on iOS WebKit because the scroll container (.modal-panel) had padding-top applied for the drag-handle. The layout was restructured — .modal-panel is now a flex column with overflow: hidden, and scrolling is delegated to .modal-panel__body. The header is always visible as a non-scrolling flex sibling. Swipe-to-close was updated accordingly.