feat(market): verified market-data snapshot to ground numeric claims

The market analyst could confabulate exact figures — citing a Bollinger
band or a "historically validated bounce" the data doesn't support (#830).
Add a deterministic get_verified_market_snapshot tool (latest OHLCV row,
common indicators, recent closes) the analyst must consult and treat as
the source of truth for any exact price/indicator claim, and instruct it
not to assert historical validation or support bounces without tool-backed
dates and prices.

#830

tradingagents/agents/utils/agent_utils.py

@@ -23,6 +23,9 @@ from tradingagents.agents.utils.news_data_tools import (
     get_insider_transactions,
     get_global_news
 )
+from tradingagents.agents.utils.market_data_validation_tools import (
+    get_verified_market_snapshot
+)
 
 logger = logging.getLogger(__name__)