Migrate authentication to Better Auth

Replace the hand-rolled JWT auth with Better Auth 1.6.25 httpOnly cookie
sessions, validated against the database on every request so revocation,
bans and role changes take effect immediately.

Backend:
- betterAuth.ts wires the Drizzle adapter, magic links, Google sign-in and
  the admin plugin; auth-schema.ts maps Better Auth's models onto the
  existing `users` table so user IDs and their foreign keys survive intact.
- routes/auth.ts is gone; Better Auth serves the standard endpoints and
  authExt.ts carries the flows it doesn't cover.
- auth.ts shrinks to session resolution and helpers; sessions/revocation in
  dashboard.ts now read and delete `auth_sessions` rows directly.
- Schema adds the Better Auth core + admin columns (email_verified, image,
  banned, ban_reason, ban_expires), with migrations and tests.
- rateLimit.ts resolves client IPs spoof-resistantly: proxy headers are only
  honoured from loopback/RFC1918 peers plus TRUSTED_PROXIES.
- passwordPolicy.ts centralises password validation.
- Bump drizzle-orm, drizzle-kit and better-sqlite3 to versions compatible
  with Better Auth.

Frontend:
- auth-client.ts plus a reworked AuthContext and api/client.ts move to
  cookie-based sessions; no more bearer tokens in requests or middleware.

photo-api:
- Validate Better Auth session cookies against the shared auth_sessions
  table instead of verifying JWTs; JWT_SECRET is no longer needed for user
  auth, and PHOTO_VIEW_SECRET now signs gallery view tokens.

BETTER_AUTH_SECRET and BETTER_AUTH_URL are required in production; the
deprecated JWT_SECRET stays only as the photo-api view-token fallback.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

backend/src/routes/tickets.ts

@@ -4,7 +4,7 @@ import { z } from 'zod';
 import { db, dbGet, dbAll, tickets, events, users, payments, paymentOptions, eventPaymentOverrides, siteSettings, isSqlite } from '../db/index.js';
 import { eq, and, or, sql, inArray } from 'drizzle-orm';
 import { requireAuth, getAuthUser } from '../lib/auth.js';
-import { generateId, generateTicketCode, getNow, toDbDate, calculateAvailableSeats, isEventSoldOut } from '../lib/utils.js';
+import { generateId, generateTicketCode, getNow, toDbDate, toDbBool, calculateAvailableSeats, isEventSoldOut } from '../lib/utils.js';
 import { createInvoice, isLNbitsConfigured, LNBITS_INVOICE_EXPIRY_SECONDS } from '../lib/lnbits.js';
 import { rateLimitMiddleware } from '../lib/rateLimit.js';
 import emailService from '../lib/email.js';
@@ -164,12 +164,15 @@ ticketsRouter.post('/', zValidator('json', createTicketSchema), async (c) => {
     user = {
       id: userId,
       email: data.email,
-      password: '', // No password for guest bookings
+      password: null, // No password for guest bookings; set on claim (Better Auth credential account)
       name: fullName,
       phone: data.phone || null,
       role: 'user',
       languagePreference: null,
       rucNumber,
+      isClaimed: toDbBool(false),
+      accountStatus: 'unclaimed',
+      emailVerified: false,
       createdAt: now,
       updatedAt: now,
     };
@@ -1429,11 +1432,14 @@ ticketsRouter.post('/admin/create', requireAuth(['admin', 'organizer', 'staff'])
     user = {
       id: userId,
       email: attendeeEmail,
-      password: '',
+      password: null,
       name: adminFullName,
       phone: data.phone || null,
       role: 'user',
       languagePreference: null,
+      isClaimed: toDbBool(false),
+      accountStatus: 'unclaimed',
+      emailVerified: false,
       createdAt: now,
       updatedAt: now,
     };
@@ -1573,11 +1579,14 @@ ticketsRouter.post('/admin/add', requireAuth(['admin', 'organizer', 'staff']), z
     user = {
       id: userId,
       email: attendeeEmail,
-      password: '',
+      password: null,
       name: fullName,
       phone: data.phone || null,
       role: 'user',
       languagePreference: null,
+      isClaimed: toDbBool(false),
+      accountStatus: 'unclaimed',
+      emailVerified: false,
       createdAt: now,
       updatedAt: now,
     };