V110 QUICK FF DEPTH AXIS CONSISTENCY

Base
- Built from v109.

Problem fixed
- In final placement, changing width with ,/. could make the depth distribution look stretched or compressed.
- The previous calculation mixed two depth coordinates: row depth based on UI fault width, plus local patch depth based on projected cell offset.

Fix
- Depth is now computed from one global down-dip map coordinate measured from the C3 epicenter.
- The same axis used to draw the preview is used to compute cell depth:
  depth = source_depth + global_down_dip_projected_distance * tan(dip)
- This keeps the preview geometry and the injected depth field consistent when ,/. changes patch width.

Kept behavior
- ,/. changes width only.
- J/K changes length only.
- Patch-local dip is still used for uplift/depth recomputation.
