V112 QUICK FINITE-FAULT EDITOR LOAD/SAVE BUTTONS

Base
- Built from v111 live color refresh branch.

What changed
- Adds Load CSV and Save CSV buttons directly inside the Quick finite-fault grid editor.
- Load CSV supports the saved editor format:
  cell,rel_s,rel_d,slip_m,delay_s,dip_deg
- It also supports a compact manual format:
  C3,12.5,60,15
  meaning cell C3 = slip 12.5 m, delay 60 s, dip 15 deg.
- Rows/Cols are restored from the saved comment when present, or expanded to fit the loaded cells.
- After loading, the editor reopens with the loaded grid size and updated cell colors.
