V78 SECONDARY DISABLED + COAST FIX

Main change
- Automatic secondary deformation generation is disabled.
- Pressing G or auto-regeneration now removes old auto-secondary nodes only.
- Finite-fault direct patches remain unchanged.
- Patch flattening remains available.

Why
- The empirical secondary-field geometry could not reliably match the desired clover/corner angle.
- The recommended workflow is now to focus on the finite-fault direct deformation only.

Coast override fix
- Correct land position is grid (564,426).
- Applied overrides:
  * 563,425 -> water
  * 564,422 -> water
  * 564,423 -> water
  * 564,424 -> water
  * 564,426 -> land
