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/azure_client.py

@@ -1,10 +1,9 @@
 import os
-from typing import Any, Optional
+from typing import Any
 
 from langchain_openai import AzureChatOpenAI
 
 from .base_client import BaseLLMClient, normalize_content
-from .validators import validate_model
 
 _PASSTHROUGH_KWARGS = (
     "timeout", "max_retries", "api_key", "reasoning_effort", "temperature",
@@ -29,7 +28,7 @@ class AzureOpenAIClient(BaseLLMClient):
         OPENAI_API_VERSION: API version (e.g. 2025-03-01-preview)
     """
 
-    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: