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/agents/schemas.py

@@ -19,11 +19,10 @@ so that:
 from __future__ import annotations
 
 from enum import Enum
-from typing import Literal, Optional
+from typing import Literal
 
 from pydantic import BaseModel, Field
 
-
 # ---------------------------------------------------------------------------
 # Shared rating types
 # ---------------------------------------------------------------------------
@@ -124,15 +123,15 @@ class TraderProposal(BaseModel):
             "the research plan. Two to four sentences."
         ),
     )
-    entry_price: Optional[float] = Field(
+    entry_price: float | None = Field(
         default=None,
         description="Optional entry price target in the instrument's quote currency.",
     )
-    stop_loss: Optional[float] = Field(
+    stop_loss: float | None = Field(
         default=None,
         description="Optional stop-loss price in the instrument's quote currency.",
     )
-    position_sizing: Optional[str] = Field(
+    position_sizing: str | None = Field(
         default=None,
         description="Optional sizing guidance, e.g. '5% of portfolio'.",
     )
@@ -196,11 +195,11 @@ class PortfolioDecision(BaseModel):
             "incorporate them; otherwise rely solely on the current analysis."
         ),
     )
-    price_target: Optional[float] = Field(
+    price_target: float | None = Field(
         default=None,
         description="Optional target price in the instrument's quote currency.",
     )
-    time_horizon: Optional[str] = Field(
+    time_horizon: str | None = Field(
         default=None,
         description="Optional recommended holding period, e.g. '3-6 months'.",
     )