checkpoint: 重写 langchain agent 前的快照

包含未合入 main 的工作:
- CAS 单点登录接入 (CasSecurityConfig + 4 个 CAS 类)
- LoginController 改 POST + body, 修 URL 密码暴露
- chat_test.py 修 texts→text typo
- 前端外部系统侧边栏 + login API POST
- gateway-nginx.conf

下一步: 从这个分支拉 feat/langgraph-rewrite 做 langchain-chat agent 重写
回滚点: git checkout backup/pre-langgraph

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

chat_web_backend/src/main/resources/application.yml

@@ -92,4 +92,17 @@ xss:
 # 词向量模型名称
 embedding-model-name: bge_m3
 
+# CAS 单点登录配置
+security:
+  cas:
+    enabled: true
+    server-host: http://192.168.203.20:8180
+    server-login: ${security.cas.server-host}/login
+    server-logout: ${security.cas.server-host}/logout
+    app-login: /cas/login
+    app-logout: /cas/logout
+    app-key: 8UyEQdr6L6FfAH3D
+    app-secret: Ely1U6Uv2Nf8APQSfZdg1epSbQ6ORKwr
+    front-end-url: http://192.168.203.8:3000
+