Multiple people: an admin adds users and chooses which tabs each may use

- Accounts: the setup code (or an existing single-user install, migrated automatically) creates the admin;
  the admin adds people in Settings -> People and gives each a one-time invite code to enrol their own passkey
- Each person's tasks, NE Hub events and subscribe link, settings, calendar links, iCloud connection and Plex
  sign-in are private, stored in their own folder (/data/users/<id>/); Plex sign-in moved from browser cookies
  into that folder (encrypted), so it also follows them across devices
- Tab access is enforced by the server (403) and reflected in the app (nav, Home, Settings, search, /api/config
  hides addresses of tabs a person cannot use); browser storage is namespaced per person
- Admin tools: change tabs, invite a device, sign out everywhere (session epoch), turn off, make/remove admin,
  delete a person and their data; the last admin cannot be removed
- Sessions carry the person (uid.epoch.expiry.signature); old single-user cookies still work as the admin
- tools/users-test.js (83 checks: isolation, access limits, invites, sign-out/disable/delete, Plex and iCloud
  per person, migration) now runs in the Gitea workflow before the image is built

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

settings.js

@@ -5,22 +5,22 @@ const path = require('path');
 const crypto = require('crypto');
 const auth = require('./auth');
 
-const DATA_DIR = process.env.DATA_DIR || path.join(__dirname, 'data');
-const FILE = path.join(DATA_DIR, 'settings.json');
+const users = require('./users');
+const file = () => path.join(users.dir(), 'settings.json'); // each person has their own
 
 // Only these keys are accepted. (Per-device things like the Seafile sign-in token and the music queue stay in the browser.)
 const KEYS = new Set(['mail_hints', 'ab_creds', 'plex_lib', 'office_loc', 'cal_default', 'cal_view', 'cal_range', 'task_list', 'task_show_done', 'recents']);
 const SECRET = new Set(['ab_creds']);
 const MAX_VALUE = 20000; // bytes of JSON per key
 
-const key = () => crypto.scryptSync(auth.secret, 'nehub-settings', 32);
+let _key; const key = () => _key || (_key = crypto.scryptSync(auth.secret, 'nehub-settings', 32));
 const seal = v => { const iv = crypto.randomBytes(12), c = crypto.createCipheriv('aes-256-gcm', key(), iv);
   const d = Buffer.concat([c.update(JSON.stringify(v), 'utf8'), c.final()]); return { _sealed: Buffer.concat([iv, c.getAuthTag(), d]).toString('base64') }; };
 const unseal = o => { try { const b = Buffer.from(o._sealed, 'base64'), d = crypto.createDecipheriv('aes-256-gcm', key(), b.subarray(0, 12));
   d.setAuthTag(b.subarray(12, 28)); return JSON.parse(Buffer.concat([d.update(b.subarray(28)), d.final()]).toString('utf8')); } catch { return undefined; } };
 
-const load = () => { try { return JSON.parse(fs.readFileSync(FILE, 'utf8')); } catch { return {}; } };
-const save = o => { fs.mkdirSync(DATA_DIR, { recursive: true }); const tmp = FILE + '.tmp'; fs.writeFileSync(tmp, JSON.stringify(o, null, 2), { mode: 0o600 }); fs.renameSync(tmp, FILE); }; // write-then-rename: a crash never leaves half a file
+const load = () => { try { return JSON.parse(fs.readFileSync(file(), 'utf8')); } catch { return {}; } };
+const save = o => { const f = file(), tmp = f + '.tmp'; fs.writeFileSync(tmp, JSON.stringify(o, null, 2), { mode: 0o600 }); fs.renameSync(tmp, f); }; // write-then-rename: a crash never leaves half a file
 const readBody = req => new Promise((ok, no) => { const c = []; let n = 0; req.on('data', d => { n += d.length; if (n > 100000) { no(new Error('Too large')); req.destroy(); } else c.push(d); }); req.on('end', () => ok(Buffer.concat(c).toString())); req.on('error', no); });
 const json = (res, code, obj) => { res.writeHead(code, { 'content-type': 'application/json' }); res.end(JSON.stringify(obj)); };