Make NAS frpc run in Container Station

- Add a NAS-specific frpc template that forwards to tuwen_web:80 over the compose network.

- Make docker-compose-Nas.yaml create tuwen_frpc by default instead of relying on Compose profiles, which Container Station may not enable.

- Remove host networking from the NAS frpc service so the tunnel works through Docker service DNS.

- Update README and Docker docs to explain the NAS frpc behavior and logs command.

docker-compose-Nas.yaml

@@ -98,17 +98,15 @@ services:
       timeout: 5s
       retries: 6
 
-  frpc:
-    # XXX 可选公网隧道客户端。启用前先编辑 frpc/frpc.toml。
+  tuwen_frpc:
+    # XXX 威联通 Container Station 通常不会启用 Compose profiles，所以 NAS 版默认启动 frpc。
+    # XXX 启用前先编辑 frpc/frpc.nas.toml；如果不需要公网映射，可删除/注释整个 tuwen_frpc 服务。
     image: snowdreamtech/frpc:latest
     container_name: tuwen_frpc
     restart: unless-stopped
-    network_mode: host
     command: ["frpc", "-c", "/etc/frp/frpc.toml"]
     volumes:
-      - ./frpc/frpc.toml:/etc/frp/frpc.toml:ro
+      - ./frpc/frpc.nas.toml:/etc/frp/frpc.toml:ro
     depends_on:
       tuwen_web:
         condition: service_healthy
-    profiles:
-      - frpc