add api tab in webui and handle invalid num_turns

lightrag/utils.py

@@ -657,6 +657,10 @@ def get_conversation_turns(
     Returns:
         Formatted string of the conversation history
     """
+    # Check if num_turns is valid
+    if num_turns <= 0:
+        return ""
+
     # Group messages into turns
     turns: list[list[dict[str, Any]]] = []
     messages: list[dict[str, Any]] = []

lightrag_webui/src/stores/settings.ts

@@ -5,7 +5,7 @@ import { defaultQueryLabel } from '@/lib/constants'
 import { Message, QueryRequest } from '@/api/lightrag'
 
 type Theme = 'dark' | 'light' | 'system'
-type Tab = 'documents' | 'knowledge-graph' | 'retrieval'
+type Tab = 'documents' | 'knowledge-graph' | 'retrieval' | 'api'
 
 interface SettingsState {
   theme: Theme