chore(lint): make the repository ruff-clean under the strict select

Clear the deferred full-repo lint backlog so the whole tree passes the strict
ruff select (E,W,F,I,B,UP,C4,SIM). Mechanical fixes dominate: import sorting,
pep585/604 annotations, dropped dead imports, and whitespace. The few semantic
changes are behavior-preserving: declare __all__ on the agent_utils and
alpha_vantage re-export hubs; expand 'from x import *' to explicit names; use
immutable tuple defaults instead of mutable list defaults; contextlib.suppress
for try/except/pass; and narrow an over-broad assertRaises.

tradingagents/llm_clients/google_client.py

@@ -1,4 +1,4 @@
-from typing import Any, Optional
+from typing import Any
 
 from langchain_google_genai import ChatGoogleGenerativeAI
 
@@ -20,7 +20,7 @@ class NormalizedChatGoogleGenerativeAI(ChatGoogleGenerativeAI):
 class GoogleClient(BaseLLMClient):
     """Client for Google Gemini models."""
 
-    def __init__(self, model: str, base_url: Optional[str] = None, **kwargs):
+    def __init__(self, model: str, base_url: str | None = None, **kwargs):
         super().__init__(model, base_url, **kwargs)
 
     def get_llm(self) -> Any: