Family board: add to shopping, tasks, checklists and the Family calendar; record who added each

- + button on each board card: write it, tap your name (PIN unless a child), it is added as you
- Tasks, events, checklist items and shopping items remember who added them
- Names shown on the board and in Tasks, Notes and Calendar
- Tests and README updated

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

public/calendar.js

@@ -27,7 +27,7 @@ const evStore = []; // events currently on screen, so a tap can open the right o
 const evRow = e => { const i = evStore.push(e) - 1;
   if (e.task) return `<div class="row it"><button class="ibtn tick" data-tt="${i}" aria-label="Mark done">${icon('check')}</button><button class="rmain" data-ei="${i}" style="text-align:left"><span class="grow"><b>${esc(e.title)}</b><small>Task due${e.t.repeat && e.t.repeat !== 'none' ? ' · repeats' : ''} · ${esc(e.cal)}</small></span></button></div>`;
   return `<button class="row" data-ei="${i}" style="text-align:left"><span class="dot" style="background:${esc(e.color)}"></span><span class="grow"><b>${esc(e.title)}</b>
-  <small>${e.allDay ? 'All day' : fmtTime(e.start) + ' – ' + fmtTime(e.end)}${e.location ? ' · ' + esc(e.location) : ''} · ${esc(e.cal)}${e.series ? ' · repeats' : ''}</small></span>${e.editable ? icon('chev', 'chev') : ''}</button>`; };
+  <small>${e.allDay ? 'All day' : fmtTime(e.start) + ' – ' + fmtTime(e.end)}${e.location ? ' · ' + esc(e.location) : ''} · ${esc(e.cal)}${e.by ? ' · added by ' + esc(e.by) : ''}${e.series ? ' · repeats' : ''}</small></span>${e.editable ? icon('chev', 'chev') : ''}</button>`; };
 document.addEventListener('click', e => {
   const tk = e.target.closest('[data-tt]');
   if (tk) { const ev = evStore[+tk.dataset.tt]; tk.disabled = true; jfetch('/api/tasks/toggle', { method: 'POST', body: JSON.stringify({ list: ev.t.list, id: ev.t.id, href: ev.t.href, done: true }) }).then(r => { if (r && r.rolled) toast('Repeats: next due ' + r.rolled); route(); }).catch(err => { tk.disabled = false; toast(err.message); }); return; }