Parent controls for children, name-tile sign-in, restricted Learn search, simple mode

- Sign-in page shows name tiles on remembered devices; tap a name, then PIN or passkey
- Music and Movies are separate on the server; Plex can be locked to a child's managed profile
- Activity log, weekly summary and alerts to parents; per-area and weekend limits
- Requests from children (Ask button) answered in Settings; bonus screen time from rewards
- Restricted Learn search (Simple English Wikipedia, blocked words) replaces web search for children
- Simple mode (big-button home) for young children or grandparents
- Child usage kept in memory instead of read from disk on every request
- Tests and README updated

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

tools/kidlimits-test.js

@@ -5,7 +5,7 @@ const users = require('../users'), kid = require('../kidlimits'), chat = require
 const ann = users.create({ name: 'Ann', role: 'admin', handle: 'YQ' }), sam = users.create({ name: 'Sam', role: 'user', tabs: ['music'], handle: 'Yg' }), pat = users.create({ name: 'Pat', role: 'user', tabs: ['music'], handle: 'Yw' });
 const asAdmin = (u, fn) => users.runAs(u, fn);
 assert.throws(() => users.update(ann.id, { kid: { on: true } }), /admin cannot be a child/, 'an admin cannot be a child account');
-users.update(sam.id, { kid: { on: true, limitMin: 3, bedtime: { on: false, from: '20:30', to: '07:00' } } }); const s0 = users.get(sam.id).kid; assert.deepEqual(s0, { on: true, limitMin: 15, bedtime: { on: false, from: '20:30', to: '07:00' }, safe: true }, 'a limit is at least 15 minutes; safe search is on unless turned off');
+users.update(sam.id, { kid: { on: true, limitMin: 3, bedtime: { on: false, from: '20:30', to: '07:00' } } }); const s0 = users.get(sam.id).kid; assert.deepEqual(s0, { on: true, limitMin: 15, weekendMin: 0, areaLimits: {}, bedtime: { on: false, from: '20:30', to: '07:00' }, safe: true }, 'a limit is at least 15 minutes; safe search is on unless turned off');
 assert.equal(users.publicView(users.get(sam.id)).kid.limitMin, 15); assert.equal(users.publicView(users.get(pat.id)).kid, undefined, 'only child accounts carry the settings');
 assert.deepEqual(kid.status(users.get(pat.id)), { on: false }); assert.equal(kid.lockedFor(users.get(pat.id), '/api/music/x'), null);
 // time counts from pings (one a minute while the app is open)