V119 QUICK FINITE-FAULT VIEWPORT EDITOR + MAP LEGEND CLEANUP

Base
- Built from v118.

Changes
- Finite-fault PNG export no longer writes the word Epicenter directly on the map panel.
- The legend/summary now uses X: Epicenter outside the map.
- Quick finite-fault editor now shows only a 5x5 bingo-style viewport of larger square cells.
- Each visible cell is a multiline input: line 1 slip, line 2 delay, line 3 dip. The old slip,delay,dip comma format still works.
- Arrow keys move the visible 5x5 window over a larger logical grid, so very large rupture models can be edited without making the window huge.
- Editor now includes Patch L km and W km fields; these become the default patch length/width used in final placement mode.
- Buttons/layout enlarged to avoid clipping.
