fix: compose passes .env through env_file; clearer name and channel messages [CI]

podman-compose does not substitute defaults inside "environment:" (a value
like ${MOSHIRO_NAME:-} reached the node as the literal text), so the node was
enrolled with an invalid name and reported the wrong network scope. The three
compose files now read .env with env_file and only interpolate image and
network_mode; the Backend .env keys are the container's own names
(MoShiro__PublicUrl, MoShiro__ClaimCode).

- The generated .env no longer carries a comment line for MOSHIRO_NAME; the
  dialog says how to choose a name instead.
- The container entrypoint prints the name it enrolls with and defaults
  MOSHIRO_NETWORK_SCOPE to host (Docker Desktop sets container in .env).
- The overview and line pages say "measurement channel not established"
  instead of "not connected": the agent can be reachable and pingable while
  the measurement TCP/UDP path is not.

docs/ops/deployment.md

@@ -48,8 +48,8 @@ Backend 使用 OCI 标准镜像，通过 `registry.oeo.one/moshiro/moshiro-backe
 mkdir moshiro-backend && cd moshiro-backend
 curl -fsSL https://git.oeo.one/justme/MoShiro/releases/download/<版本>/moshiro-compose-backend.yaml -o compose.yaml
 cat > .env <<'EOF'
-MOSHIRO_PUBLIC_URL=https://panel.example.com     # 面板对外的地址；passkey 绑定在这个域名上，改了会让已注册的 passkey 失效
-# MOSHIRO_CLAIM_CODE=                            # 认领码，不写就随机生成并打印在日志里
+MoShiro__PublicUrl=https://panel.example.com    # 面板对外的地址；passkey 绑定在这个域名上，改了会让已注册的 passkey 失效
+# MoShiro__ClaimCode=                           # 认领码（可选），不写就随机生成并打印在日志里
 EOF
 podman compose up -d        # Docker 用 docker compose
 ```
@@ -232,7 +232,6 @@ MOSHIRO_JOIN=jt_…
 MOSHIRO_GENESIS=…
 MOSHIRO_CONTROLLERS=…
 MOSHIRO_IMAGE=registry.oeo.one/moshiro/moshiro-probe
-# MOSHIRO_NAME=节点名字（不写就用主机名）
 EOF
 chmod 600 .env && curl -fsSL 'https://panel.example.com/install/compose/probe.yaml' -o compose.yaml && echo "<sha256>  compose.yaml" | sha256sum -c - && podman compose up -d
 ```