feat(news): configurable fetch params via DEFAULT_CONFIG

Per-ticker article limit, global article limit, global lookback
window, and macro query list are now read from get_config()
instead of being hardcoded. Tool wrapper get_global_news passes
None defaults so config overrides flow through the LLM-tool path
too. Macro query defaults broadened from 4 US-centric strings to
5 covering Fed, S&P 500, geopolitics, ECB/BOJ/BOE, commodities.

#606 #558 #562

tradingagents/agents/utils/news_data_tools.py

@@ -1,5 +1,5 @@
 from langchain_core.tools import tool
-from typing import Annotated
+from typing import Annotated, Optional
 from tradingagents.dataflows.interface import route_to_vendor
 
 @tool
@@ -23,16 +23,20 @@ def get_news(
 @tool
 def get_global_news(
     curr_date: Annotated[str, "Current date in yyyy-mm-dd format"],
-    look_back_days: Annotated[int, "Number of days to look back"] = 7,
-    limit: Annotated[int, "Maximum number of articles to return"] = 5,
+    look_back_days: Annotated[Optional[int], "Days to look back; omit to use the configured default"] = None,
+    limit: Annotated[Optional[int], "Max articles to return; omit to use the configured default"] = None,
 ) -> str:
     """
     Retrieve global news data.
-    Uses the configured news_data vendor.
+    Uses the configured news_data vendor. Defaults for look_back_days and
+    limit come from DEFAULT_CONFIG (global_news_lookback_days,
+    global_news_article_limit); pass explicit values to override.
+
     Args:
         curr_date (str): Current date in yyyy-mm-dd format
-        look_back_days (int): Number of days to look back (default 7)
-        limit (int): Maximum number of articles to return (default 5)
+        look_back_days (int): Number of days to look back; omit to inherit config
+        limit (int): Maximum number of articles to return; omit to inherit config
+
     Returns:
         str: A formatted string containing global news data
     """