V99 CLEANER USGS-STYLE FINITE-FAULT EXPORT

Base
- Built from the stable v95 branch as requested.

What changed
- The finite-fault PNG export is upgraded from a single rough patch panel to a cleaner 2-panel figure.
- Left panel: surrounding map/coastline image with the finite-fault patches overlaid.
- Right panel: interpolated fault-plane view that smooths and bridges patch-to-patch gaps so the model reads more like one coherent fault image.
- Adds an epicenter X marker on the map panel. The marker is placed at the centroid of the minimum-delay rupture-start patch or patches.
- Keeps direct finite-fault patch outlines visible over the smoothed fault-plane slip field.
- Keeps the slip color bar, title, patch count, max slip, and Mw summary.

Usage
- Press Ctrl+U to export.

Notes
- Only direct finite-fault stamp patches are exported.
- Auto-secondary deformation is ignored.
- The fault-plane smoothing uses Gaussian interpolation in strike/dip coordinates to reduce unnatural holes between discrete stamp patches.
