feat: Tier 1 defense-quality visualization (4 figures)

Fig 1 — VHM failure envelope with scour degradation:
  3-panel: V-H envelope at 5 scour depths, capacity reduction curves,
  radial FoS trajectory. Shows design point migrating toward failure.

Fig 2 — Cross-pipeline composite (Op3 story in one figure):
  (a) OptumGX spring profile with bucket sketch
  (b) OpenSeesPy Mode 1 shape (f1=0.2754 Hz, Mode B PISA)
  (c) OpenFAST GenPwr + RootMyc1 time series

Fig 3 — Scour progression sweep:
  4-panel mode shapes at S/D = 0, 0.1, 0.3, 0.5
  Frequency: 0.3158 → 0.3092 Hz (-2.1%)
  FoS: 1.89 → 1.29 (green → red)

Fig 4 — Mode C vs Mode D dissipation comparison:
  (a) Stiffness profile overlay with w(z) inset
  (b) f1 vs alpha calibration curve with field measurement

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Kyeong Sun Kim