- Add get_ticker() method for real-time quotes across all markets
- Add get_realtime_price() service with ticker/kline fallback chain
- Fix yfinance end date issue for US stocks and futures
- Fix forex timezone parsing for Tiingo UTC timestamps
- Add retry mechanism with exponential backoff for Tiingo API
- Add API rate limiting for portfolio (3 concurrent, 0.3s interval)
- Add force refresh option to bypass price cache on manual refresh
guopengfa