fix: use centralized settings instead of direct os.getenv for FINNHUB_API_KEY

- Remove direct os.getenv() call from news_sentiment_mcp.py
- Use backend.config.settings.finnhub_api_key for consistency
- Ensures API key is properly loaded from environment in both local and container environments

backend/mcp_servers/news_sentiment_mcp.py

@@ -17,6 +17,8 @@ from datetime import datetime, timedelta
 import httpx
 import logging
 
+from backend.config import settings
+
 logger = logging.getLogger(__name__)
 
 mcp = FastMCP("news-sentiment")
@@ -98,9 +100,8 @@ async def get_news_with_sentiment(
         )
 
     try:
-        # Get Finnhub API key from environment
-        import os
-        finnhub_api_key = os.getenv("FINNHUB_API_KEY")
+        # Get Finnhub API key from centralized settings
+        finnhub_api_key = settings.finnhub_api_key
 
         if not finnhub_api_key:
             logger.warning("FINNHUB_API_KEY not set, returning empty sentiment")