Chores: weekly goals with custom reward tiers (everyone or chosen people)

- Admin-set reward tiers; points count Monday to Sunday and restart each week
- Per-person weekly totals, chores done, progress bar toward the next reward, week history
- Mark given / undo when a reward is handed over
- Rewards can be for everyone or only chosen people
- "This week" card on the family board
- Tests and README updated

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

board.js

@@ -38,7 +38,7 @@ function identify(t, pin, req) {
 async function board(day) {
   const t1 = chores.addDays(day, 1), from = new Date(day + 'T00:00:00').getTime() - 864e5, to = new Date(t1 + 'T23:59:59').getTime() + 864e5;
   let events = []; try { events = cal.familyEvents({ from, to, fd: day, td: t1 }); } catch {}
-  return { day, people: people(), announcement: chat.announcement(), events, chores: chores.board(day).filter(i => !i.user || onBoard(users.get(i.user) || {})).map(i => ({ chore: i.chore, title: i.title, points: i.points, user: i.user, userName: i.userName, done: !!i.done, doneBy: i.done ? i.done.byName : '', claimable: !!i.claimable, claimed: !!i.claimed })), shopping: await recipes.shoppingOpen(), notes: notes.familyNotes(), tasks: tasks.familyOpen() };
+  return { day, people: people(), announcement: chat.announcement(), events, chores: chores.board(day).filter(i => !i.user || onBoard(users.get(i.user) || {})).map(i => ({ chore: i.chore, title: i.title, points: i.points, user: i.user, userName: i.userName, done: !!i.done, doneBy: i.done ? i.done.byName : '', claimable: !!i.claimable, claimed: !!i.claimed })), week: (w => ({ from: w.from, tiers: w.tiers, people: w.people.filter(p => onBoard(users.get(p.id) || {})).map(p => ({ id: p.id, name: p.name, points: p.points, count: p.count, tiers: p.tiers, earned: p.earned, given: p.given })) }))(chores.week(day)), shopping: await recipes.shoppingOpen(), notes: notes.familyNotes(), tasks: tasks.familyOpen() };
 }
 
 async function handle(req, res) {