Fix/tavily credit usage (#2314)

* Reduce Tavily search credit usage

Use basic Tavily search by default to reduce excessive credit consumption.

* Limit intelligence searches per stock

* Update test_search_tavily_provider.py

* Update pipeline.py

src/search_service.py

@@ -450,7 +450,7 @@ class TavilySearchProvider(BaseSearchProvider):
             # 执行搜索（优化：使用advanced深度、限制最近几天）
             search_kwargs: Dict[str, Any] = {
                 "query": query,
-                "search_depth": "advanced",  # advanced 获取更多结果
+                "search_depth": "basic",  # 为控制credit使用，将advanced修改成basic
                 "max_results": max_results,
                 "include_answer": False,
                 "include_raw_content": False,

tests/test_search_tavily_provider.py

@@ -76,7 +76,7 @@ class TestTavilySearchProvider(unittest.TestCase):
         self.assertEqual(_FakeTavilyClient.search_calls[0]["topic"], "news")
         self.assertEqual(_FakeTavilyClient.search_calls[0]["days"], 3)
         self.assertEqual(_FakeTavilyClient.search_calls[0]["max_results"], 5)
-        self.assertEqual(_FakeTavilyClient.search_calls[0]["search_depth"], "advanced")
+        self.assertEqual(_FakeTavilyClient.search_calls[0]["search_depth"], "basic")
         self.assertEqual(len(resp.results), 1)
         self.assertEqual(resp.results[0].published_date, published_text)
         self.assertEqual(resp.results[0].url, "https://example.com/alibaba-earnings")