241f90299c
Previously addWindow() reset all ratios to equal splits, losing any custom sizing. Now _addRatioForNewWindow() gives the new window 1/n of the space and scales the existing windows by (n-1)/n, preserving their ratios relative to each other. e.g. [1/3, 1/6, 1/2] + new → [0.25, 0.125, 0.375, 0.25]