fix: tolerate plaintext api_keys on decrypt failure

wwwroot/api/cockpit_chat.dspy

@@ -143,7 +143,12 @@ async def _build_context(sor, iteration_id, task_id, max_msgs, system_prompt):
 async def _call_llm(model_info, messages, temperature):
     """Call LLM API directly using model config from llm table."""
     api_base = model_info.api_base.rstrip('/')
-    api_key = password_decode(model_info.api_key) if model_info.api_key else ''
+    # Try decrypt; DB may have plaintext or RC4-encrypted keys
+    raw_key = model_info.api_key or ''
+    try:
+        api_key = password_decode(raw_key)
+    except Exception:
+        api_key = raw_key
     model_id = model_info.model_id
 
     headers = {