feat: 完成项目助手与监控演示并修复聊天及云部署配置

backend/graph/chat_model_options.py

@@ -0,0 +1,12 @@
+"""Explicit chat-only provider compatibility, without exposing reasoning as answers."""
+import os
+
+
+def chat_model_options():
+    mode = os.getenv("CHAT_THINKING_MODE", "").strip().lower()
+    if mode not in ("", "disabled", "enabled"):
+        raise ValueError("CHAT_THINKING_MODE 只允许 disabled、enabled 或留空")
+    options = {"timeout": 60, "max_retries": 0}
+    if mode:
+        options["extra_body"] = {"thinking": {"type": mode}}
+    return options