feat(auth): self-service password reset (backend + web)

Add a full password-reset flow — the prerequisite for the Android app
(docs/android/PLAN.md §8.2), which hands off to the website for reset
rather than shipping a native screen.

Backend:
- password_resets table: stores only the sha256 hash of an opaque 32-byte
  token (mirrors user_invites / mobile_refresh_tokens), single-use, ~1h TTL.
- model/passwordResets + users.getActiveByEmail (email is non-unique, so a
  request can match several accounts, each emailed its own link).
- mailer.sendPasswordReset (fails soft when email is unconfigured).
- Endpoints: POST /auth/password/forgot (always a generic 200 — no account
  enumeration), GET|POST /auth/password/reset/:token. Confirming rotates the
  hash and revokes every session (web cutoff + mobile refresh tokens); it does
  not auto-login, so a 2FA account still passes TOTP next sign-in. Also serves
  SSO-only accounts (null hash) as their set-initial-password path.
- Dedicated request/confirm rate limiters. Swagger regenerated.

Web:
- ForgotPassword + ResetPassword pages, routes /account/forgot and
  /account/reset/:token, and a "Forgot your password?" link on the login page.

Tests: test/passwordResets.test.js (5). All server tests pass; client builds;
end-to-end smoketest against MariaDB passes (no-enumeration, single-use, hash
rotation, session revoke, login with the new password).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NgyHnrNa8WwG3doxvxjuCr

server/src/middleware/rateLimit.js

@@ -71,6 +71,25 @@ const ssoStartLimiter = makeLimiter({
   message: 'Too many sign-in attempts. Please try again later.',
 })
 
+// Password-reset requests per IP. Each one can send email, so cap tighter than
+// login to blunt email-bombing and enumeration timing probes. The endpoint always
+// returns a generic success regardless of match, so honest users never see this.
+const passwordResetRequestLimiter = makeLimiter({
+  windowMs: 60 * 60 * 1000,
+  max: 5,
+  label: 'password-reset-request',
+  message: 'Too many reset requests. Please try again later.',
+})
+
+// Reset confirmations (token + new password) per IP. A wrong/expired token is a
+// guessing surface; the token itself is 256-bit random, but cap anyway.
+const passwordResetConfirmLimiter = makeLimiter({
+  windowMs: 15 * 60 * 1000,
+  max: 15,
+  label: 'password-reset-confirm',
+  message: 'Too many attempts. Please try again later.',
+})
+
 module.exports = {
   loginLimiter,
   registerLimiter,
@@ -78,4 +97,6 @@ module.exports = {
   contactLimiter,
   mobileRefreshLimiter,
   ssoStartLimiter,
+  passwordResetRequestLimiter,
+  passwordResetConfirmLimiter,
 }