FX.119 SuperCad Calendar: a full-page calendar in the welcome area (day, week, month, year; tasks panel; events list; .ics; search; colour and owner)

New page, left menu entry Calendar, built over the Calendar plugin's own data and editor. Day, Week, Month and Year views with Today and back/forward; calendars box (project calendar plus one per team, colour, tick to hide, scrolls); tasks panel (tasks with a due day, shown on the grid, Make event); events list for the range with a one-click .ics each; Export .ics for the ticked calendars (repeats included); search; click a day or an hour slot to add an event; events carry an optional owner (project or a team) and colour (new optional fields, older files open unchanged). Not built: drag or resize in the week view, a mini month navigator. Tests: tools/super-test/home-calendar.mjs (28). Untested: .ics in a real calendar app, phone widths on a real device. New strings are English only.