feat: Yahoo Finance SSH proxy + Xiaomi MiMo LLM support

- Add SSH proxy via foreign server for Yahoo Finance bypass
- Add fallback in load_ohlcv and get_YFin_data_online
- Add LLM JSON decode retry (3 attempts) in NormalizedChatOpenAI
- Add yahoo_proxy.py utility module
- Add test_smoke.py and patches/

tradingagents/dataflows/y_finance.py

@@ -1,13 +1,17 @@
+import logging
 from datetime import datetime
 from typing import Annotated
 
 import pandas as pd
 import yfinance as yf
+
+logger = logging.getLogger(__name__)
 from dateutil.relativedelta import relativedelta
 
 from .stockstats_utils import (
     StockstatsUtils,
     _assert_ohlcv_not_stale,
+    _yf_download_via_proxy,
     filter_financials_by_date,
     load_ohlcv,
     yf_retry,
@@ -32,7 +36,19 @@ def get_YFin_data_online(
     # end_date row (and the current day when end_date is today). Request one day
     # past end_date so the requested range is actually inclusive (#986/#987).
     end_inclusive = (end_dt + relativedelta(days=1)).strftime("%Y-%m-%d")
-    data = yf_retry(lambda: ticker.history(start=start_date, end=end_inclusive))
+    try:
+        data = yf_retry(lambda: ticker.history(start=start_date, end=end_inclusive))
+    except Exception:
+        # Fallback: use SSH proxy via foreign server
+        logger.warning(f"Yahoo Finance local failed for {symbol}, trying SSH proxy...")
+        proxy_df = _yf_download_via_proxy(canonical, start_date, end_inclusive)
+        if proxy_df.empty:
+            raise NoMarketDataError(
+                symbol, canonical, f"no rows between {start_date} and {end_date} (proxy also failed)"
+            )
+        # Convert to match expected format
+        proxy_df = proxy_df.set_index("Date")
+        data = proxy_df
 
     # Empty result means the symbol is unknown/delisted. Raise a typed error
     # instead of returning prose: the routing layer turns it into a single