V107 QUICK FINITE-FAULT ORIENTATION + DEPTH FIX

Base
- Built from V106 quick finite-fault grid-size controls.

Fixes
- The strike/down-dip "ㅏ" orientation symbol is now drawn from the exact same strike/down-dip basis used by the patch preview, so it rotates with Z/X together with the preview rectangles.
- Patch center spacing in the down-dip direction now uses each patch cell's own dip-projected width.
- Each patch now gets its own calculated depth:
  depth = source_depth_km + rel_d * fault_width_km * sin(dip)
  where C3 has rel_d=0, rows above C3 are shallower, and rows below C3 are deeper.
- Slip-to-uplift height is now rebuilt from each patch's own slip, dip, and calculated depth, and that depth is saved into stamp_depth_km metadata for the generated sources.
