chore: reduce MyBatis SQL session debug noise

Lower MyBatis/JDBC logging to INFO to avoid high-frequency
SqlSessionUtils debug spam during RAG processing.

backend/lingyue-starter/src/main/resources/application.properties

@@ -95,7 +95,7 @@ rag.chunk.overlap=50
 rag.search.top-k=3
 
 # RAG 自动索引配置
-rag.auto-index.enabled=false
+rag.auto-index.enabled=true
 
 # XSS防护配置
 xss.enabled=true
@@ -113,6 +113,10 @@ logging.level.root=INFO
 logging.level.com.lingyue=INFO
 logging.level.org.springframework=WARN
 logging.level.org.springframework.web=INFO
+logging.level.org.mybatis.spring.SqlSessionUtils=INFO
+logging.level.org.mybatis.spring=INFO
+logging.level.org.springframework.jdbc=INFO
+logging.level.com.baomidou.mybatisplus=INFO
 
 # Nacos配置（单体应用禁用服务发现）
 spring.cloud.nacos.discovery.enabled=false