feat(infra): add hub service — Docker, Traefik, CI/CD

- Add infra/docker/hub.Dockerfile (Next.js multi-stage build)
- Add infra/compose/hub.yml with app-shared-net
- Add Traefik route for hub.asepharyana.{my,web}.id → hub:3000
- Update docker-build-push.yml: path detection, matrix build, dispatch, manifest
- Update deploy-docker.yml: include hub.yml in ALL_COMPOSE_FILES
- Update update-submodule.yml: allow hub service
- Update docs/ARCHITECTURE.md

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

infra/compose/hub.yml

@@ -0,0 +1,16 @@
+services:
+  hub:
+    container_name: hub
+    image: ghcr.io/asepharyana/asepharyana-hub/hub:sha-TODO
+    restart: always
+    networks:
+      app-shared-net:
+        aliases:
+          - hub
+    env_file:
+      - ../../.env
+
+networks:
+  app-shared-net:
+    name: app-shared-net
+    external: true