fix: add LITELLM_API_KEY support for authenticated LiteLLM calls

dashboard/backend/services/agents/base_agent.py

@@ -18,6 +18,7 @@ class BaseAgent:
         self.system_prompt = system_prompt
         self.config = config
         self.litellm_url = os.getenv("LITELLM_URL", "http://litellm:4005")
+        self.litellm_api_key = os.getenv("LITELLM_API_KEY", "")
 
     async def execute(self, task: Dict[str, Any], context: Dict[str, Any]) -> Dict[str, Any]:
         """
@@ -79,9 +80,14 @@ Only propose actions you can actually execute. Be specific and actionable."""
         temperature = self.config.get("temperature", 0.7)
 
         try:
+            headers = {}
+            if self.litellm_api_key:
+                headers["Authorization"] = f"Bearer {self.litellm_api_key}"
+
             async with httpx.AsyncClient(timeout=60.0) as client:
                 response = await client.post(
                     f"{self.litellm_url}/chat/completions",
+                    headers=headers,
                     json={
                         "model": model,
                         "messages": [