Harden sync and security; add IQ Bible, templates, password reset, backups

Sync and data safety
- Autosave flushes on leaving a study or the tab; storage-full errors are reported
- Unsynced studies, deletes and ink are queued and retried when back online
- Deletes propagate across devices (with a "Keep it" undo) and no longer resurrect
- Server assigns study versions (no client-clock conflicts); "Combine both"
  merges a conflicted study chunk by chunk
- Reading-plan progress made offline is merged, not overwritten; plans, ink and
  marks are cleared from the device on sign-out

Security
- Block SSRF through the ntfy reminder URL; failure-only rate limiting per IP and
  account; constant-time login; TOTP replay protection; input validation;
  SESSION_SECRET required in production; admin user delete fixed
- Forgot password: one-time code sent to the account's ntfy topic

Features
- IQ Bible proxy (route allow-list, text-only caching per its terms): more
  commentaries, lexicons, study aids, daily verse and devotional, plan calendar
  export, narrations, podcast background
- Study templates, reading-plan catch-up, account export, daily database snapshots

Tests and tooling
- ESLint config; App tests split into src/test; tests for sync queues, library
  hook, merge, templates, IQ Bible UI and reset form

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

server/reminders.test.js

@@ -1,6 +1,7 @@
 // @vitest-environment node
 import http from 'node:http';
 import { test, expect, afterEach } from 'vitest';
+process.env.ALLOW_PRIVATE_NTFY = '1'; // the tests talk to a local server
 import { isDue, isValidTimeZone, reminderBody, sendNtfy, sendTestReminder, zonedNow } from './reminders.js';
 
 const at = (iso) => new Date(iso);
@@ -84,3 +85,17 @@ test('an ntfy error response becomes a readable failure', async () => {
 test('an unreachable server says so instead of hanging', async () => {
   await expect(sendNtfy({ ntfyUrl: 'http://127.0.0.1:9', ntfyTopic: 'abc' }, { title: 't', body: 'b' })).rejects.toThrow(/Could not reach/);
 });
+
+test('private and loopback addresses are rejected as reminder servers', async () => {
+  const { isPrivateAddress, assertPublicUrl, readToday } = await import('./reminders.js');
+  for (const a of ['127.0.0.1', '10.1.2.3', '192.168.0.5', '172.16.0.1', '169.254.169.254', '::1', 'fd00::1', '::ffff:10.0.0.1']) expect(isPrivateAddress(a)).toBe(true);
+  expect(isPrivateAddress('8.8.8.8')).toBe(false);
+  const prev = process.env.ALLOW_PRIVATE_NTFY;
+  delete process.env.ALLOW_PRIVATE_NTFY;
+  await expect(assertPublicUrl('http://localhost:3001')).rejects.toThrow();
+  await expect(assertPublicUrl('http://169.254.169.254/latest')).rejects.toThrow();
+  await expect(assertPublicUrl('ftp://example.com')).rejects.toThrow();
+  process.env.ALLOW_PRIVATE_NTFY = prev;
+  expect(readToday({ activity: ['2026-09-29'] }, '2026-09-29')).toBe(true);
+  expect(readToday({ activity: [] }, '2026-09-29')).toBe(false);
+});