Leetcode 2258. Escape the Spreading Fire

Given a grid with grass, fire, and impassable walls, determine the maximum minutes you can wait at (0,0) before starting to move so that you can still reach (m-1,n-1) safely (return -1 if impossible, 1e9 if always safe). The core challenge is reasoning about two competing time-evolving spreads — multi-source fire propagation vs. your timed path — to decide feasibility for different start delays.