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>

users.js

@@ -62,6 +62,7 @@ function update(id, patch) {
   }
   if (patch.kid !== undefined) { const k = require('./kidlimits').cleanKid(patch.kid); if (u.role === 'admin' && k && k.on) throw new Error('An admin cannot be a child account'); if (k) u.kid = k; else delete u.kid; }
   if (patch.board !== undefined) { if (patch.board === false) u.board = false; else delete u.board; } // whether they are on the family board and in family chore progress
+  if (patch.simple !== undefined) { if (patch.simple) u.simple = true; else delete u.simple; } /* simple mode: a big-button layout with few choices */
   if (patch.signOutEverywhere) u.epoch++;
   save(); return u;
 }
@@ -75,7 +76,7 @@ function remove(id) {
 
 const can = (u, tab) => !!u && (ALWAYS.includes(tab) || u.role === 'admin' || (u.tabs || []).includes(tab));
 const allowedTabs = u => !u ? [] : [...ALWAYS, ...(u.role === 'admin' ? TABS : (u.tabs || []).filter(t => TABS.includes(t)))];
-const publicView = u => ({ id: u.id, name: u.name, role: u.role, tabs: allowedTabs(u), disabled: !!u.disabled, created: u.created, ...(u.kid && u.kid.on ? { kid: u.kid } : {}), board: u.board !== false });
+const publicView = u => ({ id: u.id, name: u.name, role: u.role, tabs: allowedTabs(u), disabled: !!u.disabled, created: u.created, ...(u.kid && u.kid.on ? { kid: u.kid } : {}), board: u.board !== false, simple: !!u.simple });
 
 // ---- A single-user install becomes "the admin" without anyone doing anything: their passkey, tasks, events, settings,
 // iCloud connection and calendar links move into their own folder. (Copied, so the originals stay as a backup.)