feat(ads): add OpenRouter support and configurable model parameters in AI evaluations

backend/ads/tasks.py

@@ -37,7 +37,12 @@ def evaluate_ad_with_ai(self, evaluation_id):
         return
 
     try:
-        client = OpenAI(api_key=api_key)
+        # Support OpenRouter keys seamlessly
+        client_kwargs = {"api_key": api_key}
+        if api_key.startswith("sk-or-"):
+            client_kwargs["base_url"] = "https://openrouter.ai/api/v1"
+
+        client = OpenAI(**client_kwargs)
         
         system_instruction = (
             "You are an expert Iranian market analyst. Your job is to read listing descriptions "
@@ -53,13 +58,17 @@ def evaluate_ad_with_ai(self, evaluation_id):
             f"Ad Description:\n{ad.description}"
         )
         
+        default_model = "openrouter/free" if api_key.startswith("sk-or-") else "gpt-4o-mini"
+        model_name = os.getenv("OPENAI_MODEL", default_model)
+        
         completion = client.beta.chat.completions.parse(
-            model="gpt-4o-mini",
+            model=model_name,
             messages=[
                 {"role": "system", "content": system_instruction},
                 {"role": "user", "content": user_content}
             ],
             response_format=AdEvaluationResult,
+            max_tokens=300,
             timeout=25
         )