cross-domain slices 2-3: events + shop peers, full workflow operable from the web UI

The whole vision, clickable end-to-end across THREE fed-sx peers (blog / events / shop), each a
lib/host instance with SX_DOMAIN-selected types + behaviors.

- EVENTS peer: a 'calendar' type (on-allocate → real allocated relation, via the driver now
  PERFORMING relate effects) + an 'event' type. /calendars UI: allocated posts, scheduled events
  (each with its featured post + a Buy-ticket button + sold count), and a Schedule-an-event form.
  host/blog-new-event schedules an event on main, optionally featuring an allocated post.
- SHOP peer: an 'order' type. POST /order?event= creates an order (is-a order, related to the event)
  → 'order:<id>'. Replaces the Python shop service.
- BUY: events POSTs a cross-domain order to shop (host/blog--http-order), then links event--sold-->
  order. host/blog--out-raw reads cross-domain edges (host/blog-out filters to local slugs, which
  would drop federated refs — the bug that hid allocated posts + sold counts).
- BLOG: every post page shows an 'Allocate to a calendar' form.
- serve.sh: SX_DOMAIN gates blog/events/shop seeds; SX_EVENTS_BASE / SX_SHOP_BASE wire the chain.
  docker-compose: sx_events + sx_shop peers (own stores, shared fed secret, externalnet-ready).

LIVE, all via the browser: allocate 'welcome' on blog → events /calendars shows it → schedule
'Summer Gig' featuring welcome → Buy ticket → shop order → tickets sold increments. blog 218/218.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker-compose.dev-sx-host.yml

@@ -108,6 +108,8 @@ services:
       SX_ACTOR: "events.rose-ash.com"
       SX_SELF_URL: "http://sx_events:8000"
       SX_FED_SECRET: "rose-ash-fed-2026-shared-a3f9"
+      # Cross-domain: where to place ticket orders (the shop peer).
+      SX_SHOP_BASE: "http://sx_shop:8000"
     volumes:
       - ./spec:/app/spec:ro
       - ./lib:/app/lib:ro
@@ -122,6 +124,41 @@ services:
       - default
     restart: unless-stopped
 
+  # The SHOP domain — a fed-sx peer running lib/host with SX_DOMAIN=shop (an "order" type). Events
+  # places ticket orders here (POST /order). Replaces the Python shop/market service.
+  sx_shop:
+    image: registry.rose-ash.com:5000/sx_docs:latest
+    container_name: sx-dev-sx_shop-1
+    entrypoint: ["bash", "/app/lib/host/serve.sh"]
+    working_dir: /app
+    environment:
+      SX_PROJECT_DIR: /app
+      SX_SERVER: /app/bin/sx_server
+      HOST_PORT: "8000"
+      SX_HTTP_HOST: "0.0.0.0"
+      SX_PERSIST_DIR: /data/persist
+      SX_ADMIN_USER: admin
+      SX_ADMIN_PASSWORD: "sx-shop-camper-2026"
+      SX_SESSION_SECRET: "shop-sess-9d2e1f"
+      SX_SERVING_JIT: "1"
+      OCAMLRUNPARAM: "b"
+      SX_DOMAIN: "shop"
+      SX_ACTOR: "shop.rose-ash.com"
+      SX_SELF_URL: "http://sx_shop:8000"
+      SX_FED_SECRET: "rose-ash-fed-2026-shared-a3f9"
+    volumes:
+      - ./spec:/app/spec:ro
+      - ./lib:/app/lib:ro
+      - ./next:/app/next:ro
+      - ./web:/app/web:ro
+      - ./shared/static:/app/shared/static:ro
+      - ./hosts/ocaml/_build/default/bin/sx_server.exe:/app/bin/sx_server:ro
+      - /root/sx-shop-persist:/data/persist
+    networks:
+      - externalnet
+      - default
+    restart: unless-stopped
+
 networks:
   externalnet:
     external: true