feat: add space subdomain routing and ownership support

- Traefik wildcard HostRegexp for <space>.r*.online subdomains
- Middleware subdomain extraction and path rewriting
- Provision endpoint with owner_did acknowledgement
- Registry enforces space ownership via EncryptID JWT

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -4,7 +4,7 @@ services:
     restart: unless-stopped
     labels:
       - "traefik.enable=true"
-      - "traefik.http.routers.rswag.rule=Host(`rswag.online`) || Host(`www.rswag.online`)"
+      - "traefik.http.routers.rswag.rule=Host(`rswag.online`) || Host(`www.rswag.online`) || HostRegexp(`{subdomain:[a-z0-9-]+}.rswag.online`)"
       - "traefik.http.services.rswag.loadbalancer.server.port=80"
     healthcheck:
       test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://127.0.0.1:80/"]