Fix: switch to Llama-3.2-3B-Instruct chat model

app.py

@@ -3,7 +3,7 @@ import os
 from huggingface_hub import InferenceClient
 
 client = InferenceClient(
-    model="mistralai/Mistral-7B-Instruct-v0.3",
+    model="meta-llama/Llama-3.2-3B-Instruct",
     token=os.environ.get("HF_TOKEN")
 )
 
@@ -11,7 +11,7 @@ def generate_dockerfile(description, base_os, app_type):
     messages = [
         {
             "role": "system",
-            "content": "You are a DevOps expert. Return ONLY Dockerfile content, no explanation."
+            "content": "You are a DevOps expert. Return ONLY Dockerfile content, no explanation, no markdown."
         },
         {
             "role": "user",