V103 QUICK FINITE-FAULT EDITOR / STAMP REPLACEMENT

Base
- Built from v102.

Main change
- The old S finite-fault stamp workflow is replaced by a quick finite-fault table editor plus final placement mode.

Workflow
1. Press S.
2. A separate Quick finite-fault editor opens.
3. Edit rows like a small CSV/Excel-style table:
   - RelS: relative along-strike position from epicenter, in patch-length units
   - RelD: relative down-dip/across position from epicenter, in patch-width units
   - Slip m
   - Delay s
   - Dip deg
4. Use Color: Slip or Color: Delay to recolor the table rows.
   - 0% starts white
   - 20% cyan
   - 40% green
   - 60% yellow/orange
   - 100% red
5. Close or Apply/Placement. The editor asks whether to save CSV; if not saving, it asks for confirmation.
6. After that, final placement mode starts. Move the mouse to the epicenter; a magenta preview follows the cursor.
7. Click or press Enter to apply the finite fault.

Final placement controls
- Z/X: rotate strike
- J/K: patch length
- </>: patch width while keeping aspect
- S: reopen editor
- Esc: cancel placement

Notes
- The table does not ask for lat/lon, strike, or patch size. Those are decided at final placement.
- The clicked/mouse location becomes the epicenter/relative-origin position.
- Direct finite-fault nodes are written with slip, delay, dip, width, length, depth and strike metadata so existing Mw and USGS-style export continue to work.
