Deployment Redesign

Implemented the deployment redesign.
- Added Dockge-first-class stacks:
  - [stacks/infra/compose.yaml]
  - [stacks/caddy/compose.yaml]
- Added reusable business template: [deploy/business-compose.yaml.template]
- Added automated provisioning: [scripts/create-business.sh]
- Added per-business database/user, secrets, media volume, private networks, and Caddy route generation.
- Removed Traefik and manual business Compose files.
- Updated environment templates, .gitignore, and deployment documentation in [README.md]
Validation completed:
- Docker Compose config passed for infra, Caddy, and generated business stacks.
- Shell syntax validation passed.
- Registry image tags containing / were tested.
- No remaining Traefik or obsolete deployment references found.

deploy/business-compose.yaml.template

@@ -0,0 +1,35 @@
+name: nextchair-${BUSINESS_SLUG}
+
+# Generated by scripts/create-business.sh. Keep this file self-contained so
+# Dockge can operate this business independently.
+
+services:
+  nextchair-${BUSINESS_SLUG}:
+    image: ${NEXTCHAIR_IMAGE:-nextchair:latest}
+    container_name: nextchair-${BUSINESS_SLUG}
+    restart: unless-stopped
+    env_file:
+      - .env
+    volumes:
+      - nextchair-media-${BUSINESS_SLUG}:/app/storage/media
+    healthcheck:
+      test: ["CMD", "node", "-e", "require('http').get('http://localhost:3000/api/health', r => process.exit(r.statusCode === 200 ? 0 : 1)).on('error', () => process.exit(1))"]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+      start_period: 20s
+    networks:
+      - nextchair-proxy
+      - nextchair-db
+
+volumes:
+  nextchair-media-${BUSINESS_SLUG}:
+    name: nextchair-media-${BUSINESS_SLUG}
+
+networks:
+  nextchair-proxy:
+    name: nextchair-proxy
+    external: true
+  nextchair-db:
+    name: nextchair-db
+    external: true