- Replace card-based agenda layout with a 6-column table (Nr, Zeit, Dauer, Titel, Verantwortlich, Aktionen)
- Fix isHeaderType to only match type=header, not all non-song items
- Format start time from ISO 8601 to HH:MM (Europe/Berlin)
- Format duration from seconds string to H:MM
- Fix responsible parsing for CTS data structure ({text, persons[{person:{title}}]})
- Move unmatched song search/assign UI into ArrangementDialog popup
- Add colored row backgrounds (song/sermon/announcement/slides) with left border
- Invert header rows to dark grey background with white text
- Transform arrangement data in Edit.vue to flat {id, name, color, slides}
format expected by ArrangementDialog (was passing raw Eloquent structure
with nested arrangement_groups[].group instead of flat .groups[])
- Stop arrangement select change from closing the dialog (only close on X)
- Fallback to all available groups when no arrangement selected (Master)
