feat: 全面SSH中转代理 + mimo-v2.5-pro支持

- Yahoo Finance: 跳过本地限流，直接走SSH中转
- StockTwits: 直连403时自动fallback到SSH中转
- Reddit: 网络不可达时自动fallback到SSH中转
- Polymarket: 网络不可达时自动fallback到SSH中转
- FRED: 配置API Key (825283926dd016ea66e96cc919e047da)
- .env: 新增FRED_API_KEY和OPENAI_COMPATIBLE_API_KEY
- test_xiaomi.py: 小米mimo-v2.5-pro测试脚本

tradingagents/dataflows/y_finance.py

@@ -36,19 +36,15 @@ 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")
-    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
+    # Skip local Yahoo Finance (rate-limited), go directly through SSH proxy
+    logger.info(f"Yahoo Finance: fetching {canonical} via 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 failed)"
+        )
+    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