更新文档，添加本地服务安装说明和配置示例

config.example.yaml

@@ -1,15 +1,21 @@
+# Copy this file to config.yaml and replace placeholders with local values.
+# Do not commit config.yaml because it may contain backend root keys.
+
 server:
   host: "127.0.0.1"
   port: 1934
+  # Optional key that protects Memory Gateway itself. Leave empty for local dev.
   api_key: ""
 
 openviking:
+  # OpenViking HTTP server. The api_key must match server.root_api_key in ov.conf.
   url: "http://127.0.0.1:1933"
-  api_key: "your-secret-root-key"
+  api_key: "<OPENVIKING_ROOT_KEY>"
   timeout: 30
   verify_ssl: true
 
 everos:
+  # EverOS EverCore HTTP server.
   url: "http://127.0.0.1:1995"
   api_key: ""
   timeout: 180
@@ -17,7 +23,7 @@ everos:
   health_path: "/health"
 
 storage:
-  sqlite_path: "/home/tom/memory-gateway/memory_system_api.sqlite3"
+  sqlite_path: "./memory_system_api.sqlite3"
 
 logging:
   level: "INFO"