feat: 收敛知识库检索调度与评分语义

- 固定 rag.engine 与 Milvus 配置，补齐启动期检索基础设施校验

- 支持调用方配置 retrievalMode，并统一知识库检索入口与结果来源展示

- 修正关键词检索 knowledgeId 过滤、混合检索评分归一化与本地 ES 默认配置

docker-compose.middleware.yml

@@ -118,7 +118,32 @@ services:
       minio-init:
         condition: service_completed_successfully
     ports:
-      - "19530:19530"
+      - "39530:19530"
       - "9091:9091"
     volumes:
       - ./data/milvus:/var/lib/milvus
+
+  elasticsearch:
+    image: docker.elastic.co/elasticsearch/elasticsearch:8.15.5
+    container_name: easyflow-elasticsearch
+    restart: unless-stopped
+    environment:
+      TZ: Asia/Shanghai
+      discovery.type: single-node
+      ELASTIC_PASSWORD: elastic
+      xpack.security.enabled: "true"
+      ES_JAVA_OPTS: -Xms1g -Xmx1g
+    ports:
+      - "39200:9200"
+    volumes:
+      - ./data/elasticsearch:/usr/share/elasticsearch/data
+    healthcheck:
+      test:
+        [
+          "CMD-SHELL",
+          "curl -fsS -u elastic:elastic http://127.0.0.1:9200 >/dev/null || exit 1",
+        ]
+      interval: 15s
+      timeout: 10s
+      retries: 20
+      start_period: 60s