QuantConnect Lean Version 18200 Fixes GetMarketHours Boundary Issues for Early Close and Delayed Open

QuantConnect Lean Version 18200 fixes boundary anomalies in the GetMarketHours function for early close and delayed open scenarios. It resolves the error where a delayed open later than all trading sessions on the same day incorrectly returned the full regular trading session, while also eliminating zero-length trading sessions caused by boundary time points. This version adds regression tests for corresponding scenarios, developed jointly by abhi-byte62 and Claude Opus 5.5.