Initial commit: WebMail Gateway with PKCE support

- Multi-tenant routing support
- Keycloak SSO integration with PKCE
- Basic inbox functionality
- Redis session management

docker-compose.yml

@@ -0,0 +1,32 @@
+services:
+  webmail-gateway:
+    build: .
+    container_name: webmail-gateway
+    environment:
+      - REDIS_HOST=10.1.0.20
+      - REDIS_PORT=6379
+      - REDIS_PASSWORD=DC1qaz2wsx
+      - REDIS_DB=2
+      - DATABASE_URL=postgresql://admin:DC1qaz2wsx@10.1.0.20:5433/virtual_mis
+      - KEYCLOAK_SERVER_URL=https://auth.lab.taipei
+      - KEYCLOAK_REALM=vmis-admin
+      - KEYCLOAK_CLIENT_ID=vmis-services
+      - KEYCLOAK_CLIENT_SECRET=VirtualMIS2026ServiceSecret12345
+      - REDIRECT_URI=https://webmail.lab.taipei/callback
+    networks:
+      - traefik-network
+      - mailserver_mailserver-internal
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik-network"
+      - "traefik.http.routers.webmail.rule=Host(`webmail.lab.taipei`)"
+      - "traefik.http.routers.webmail.entrypoints=web,websecure"
+      - "traefik.http.routers.webmail.tls.certresolver=letsencrypt"
+      - "traefik.http.services.webmail.loadbalancer.server.port=8000"
+    restart: always
+
+networks:
+  traefik-network:
+    external: true
+  mailserver_mailserver-internal:
+    external: true