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/dataflows/market_data_validator.py

@@ -10,7 +10,7 @@ claim. Deterministic, no LLM involved.
 
 from __future__ import annotations
 
-from typing import Iterable, Optional
+from collections.abc import Iterable
 
 import pandas as pd
 from stockstats import wrap
@@ -63,7 +63,7 @@ def build_verified_market_snapshot(
     symbol: str,
     curr_date: str,
     look_back_days: int = 30,
-    indicators: Optional[Iterable[str]] = None,
+    indicators: Iterable[str] | None = None,
 ) -> str:
     """Render a ground-truth snapshot: latest OHLCV row, indicators, recent closes."""
     # `df` keeps the original capitalized OHLCV columns (Open/High/Low/Close/