Add email verification, personal calendar feed, and full SEO implementation

- Customer accounts now require email verification (hashed, single-use,
  time-limited tokens) before they can request/confirm bookings, with
  resend flows on login/account/booking widget and rate limiting.
- Admins get a private, rotatable iCalendar (ICS) subscription feed of
  their confirmed bookings and public events, timezone-correct for
  Europe/Berlin including DST, never exposing meeting passwords.
- Adds a full SEO layer: per-page canonical/OG/Twitter metadata with
  CMS-editable overrides and content-derived fallbacks, a dynamic
  sitemap.xml and robots.txt driven by real published content, JSON-LD
  (Organization/LocalBusiness, WebSite, WebPage, BreadcrumbList, Service,
  Event, BlogPosting) that never fabricates data, and a CMS-managed
  redirect table for changed slugs.
- Global ANOUMA-naming audit: the brand name is never used to label
  personal account/calendar areas anywhere in the app, CMS, or emails.

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

collections/Offers.ts

@@ -1,6 +1,7 @@
 import type { CollectionConfig } from "payload";
 import { isAdmin, publishedOrAdmin } from "@/access";
 import { slugField } from "@/fields/slug";
+import { seoFields } from "@/fields/seo";
 
 // Groups the 7 individual offers for the mega menu and the /angebote
 // overview page (Kindergruppen bundles Erdenkinder + Mädchenkreis, Singkreise
@@ -123,5 +124,6 @@ export const Offers: CollectionConfig = {
         },
       ],
     },
+    seoFields(),
   ],
 };