Add langsmith vars to dockerfile

Dockerfile

@@ -12,6 +12,11 @@ ENV HOME=/home/user \
 
 ENV UVICORN_WS_PROTOCOL=websockets
 
+# Set Langsmith environment variables with defaults
+ENV LANGSMITH_TRACING=true \
+    LANGSMITH_ENDPOINT="https://api.smith.langchain.com" \
+    LANGSMITH_PROJECT="inference-endpoints"
+
 # Set the working directory
 WORKDIR $HOME/app