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/stocktwits.py

@@ -20,6 +20,7 @@ import logging
 from urllib.request import Request, urlopen
 
 from .symbol_utils import crypto_base
+from .stockstats_utils import _fetch_via_ssh
 
 logger = logging.getLogger(__name__)
 
@@ -54,8 +55,13 @@ def fetch_stocktwits_messages(ticker: str, limit: int = 30, timeout: float = 10.
     except (OSError, http.client.HTTPException, json.JSONDecodeError) as exc:
         # OSError covers URLError/TimeoutError/connection resets; HTTPException
         # covers chunked-transfer errors (IncompleteRead/BadStatusLine, #1024).
-        logger.warning("StockTwits fetch failed for %s: %s", ticker, exc)
-        return f"<stocktwits unavailable: {type(exc).__name__}>"
+        logger.warning("StockTwits direct fetch failed for %s: %s, trying SSH proxy...", ticker, exc)
+        try:
+            proxy_data = _fetch_via_ssh(url, timeout=timeout)
+            data = json.loads(proxy_data)
+        except Exception as proxy_exc:
+            logger.warning("StockTwits proxy also failed for %s: %s", ticker, proxy_exc)
+            return f"<stocktwits unavailable: {type(exc).__name__}>"
 
     messages = data.get("messages", []) if isinstance(data, dict) else []
     if not messages: