chore(P14-8): 完成运营化与验收收口

server/.env.example

@@ -19,8 +19,9 @@ STORAGE_DIR="generated/storage"
 SIGNED_URL_TTL_SECONDS="600"
 MAX_UPLOAD_SIZE_BYTES="10485760"
 
-# ===== Metrics（Prometheus）=====
+# ===== Metrics（Prometheus & OpenTelemetry）=====
 # METRICS_ENABLED="true"
+# OTEL_TRACES_ENABLED="false"
 
 # ===== 单域托管 client/dist（试运行/生产建议）=====
 # SERVE_CLIENT_DIST="true"