fix: bundle config/recursion/missing-key fixes

- dataflows/config: deepcopy + one-level dict merge so a partial
  set_config doesn't clobber sibling defaults
- graph: thread max_recur_limit from config to Propagator
- openai_client: name the missing env var in the API-key error

#788 #764 #680

tests/conftest.py

@@ -19,6 +19,8 @@ _API_KEY_ENV_VARS = (
     "DEEPSEEK_API_KEY",
     "DASHSCOPE_API_KEY",
     "ZHIPU_API_KEY",
+    "MINIMAX_API_KEY",
+    "MINIMAX_CN_API_KEY",
     "OPENROUTER_API_KEY",
     "AZURE_OPENAI_API_KEY",
     "ALPHA_VANTAGE_API_KEY",

tests/test_dataflows_config.py

@@ -0,0 +1,61 @@
+"""Config isolation: get/set must not leak nested-dict references."""
+
+import copy
+import unittest
+
+import pytest
+
+import tradingagents.default_config as default_config
+from tradingagents.dataflows.config import get_config, set_config
+
+
+@pytest.mark.unit
+class DataflowsConfigIsolationTests(unittest.TestCase):
+    def setUp(self):
+        set_config(copy.deepcopy(default_config.DEFAULT_CONFIG))
+
+    def test_get_config_returns_deep_copy(self):
+        cfg = get_config()
+        cfg["data_vendors"]["core_stock_apis"] = "alpha_vantage"
+        cfg["tool_vendors"]["get_stock_data"] = "alpha_vantage"
+
+        fresh = get_config()
+        self.assertEqual(fresh["data_vendors"]["core_stock_apis"], "yfinance")
+        self.assertNotIn("get_stock_data", fresh["tool_vendors"])
+
+    def test_set_config_does_not_alias_caller_nested_dicts(self):
+        custom = copy.deepcopy(default_config.DEFAULT_CONFIG)
+        custom["data_vendors"]["core_stock_apis"] = "alpha_vantage"
+        custom["tool_vendors"]["get_stock_data"] = "alpha_vantage"
+
+        set_config(custom)
+
+        custom["data_vendors"]["core_stock_apis"] = "yfinance"
+        custom["tool_vendors"]["get_stock_data"] = "yfinance"
+
+        fresh = get_config()
+        self.assertEqual(fresh["data_vendors"]["core_stock_apis"], "alpha_vantage")
+        self.assertEqual(fresh["tool_vendors"]["get_stock_data"], "alpha_vantage")
+
+    def test_partial_nested_update_preserves_existing_defaults(self):
+        set_config(
+            {
+                "data_vendors": {
+                    "core_stock_apis": "alpha_vantage",
+                }
+            }
+        )
+
+        fresh = get_config()
+        self.assertEqual(fresh["data_vendors"]["core_stock_apis"], "alpha_vantage")
+        self.assertEqual(fresh["data_vendors"]["technical_indicators"], "yfinance")
+        self.assertEqual(fresh["data_vendors"]["fundamental_data"], "yfinance")
+        self.assertEqual(fresh["data_vendors"]["news_data"], "yfinance")
+
+    def test_nested_dict_updates_merge_one_level_deep(self):
+        set_config({"tool_vendors": {"get_stock_data": "alpha_vantage"}})
+        set_config({"tool_vendors": {"get_news": "alpha_vantage"}})
+
+        fresh = get_config()
+        self.assertEqual(fresh["tool_vendors"]["get_stock_data"], "alpha_vantage")
+        self.assertEqual(fresh["tool_vendors"]["get_news"], "alpha_vantage")