feat: Add OPD method support to Zernike visualization with Standard/OPD toggle

Major improvements to Zernike WFE visualization:

- Add ZernikeDashboardInsight: Unified dashboard with all orientations (40°, 60°, 90°)
  on one page with light theme and executive summary
- Add OPD method toggle: Switch between Standard (Z-only) and OPD (X,Y,Z) methods
  in ZernikeWFEInsight with interactive buttons
- Add lateral displacement maps: Visualize X,Y displacement for each orientation
- Add displacement component views: Toggle between WFE, ΔX, ΔY, ΔZ in relative views
- Add metrics comparison table showing both methods side-by-side

New extractors:
- extract_zernike_figure.py: ZernikeOPDExtractor using BDF geometry interpolation
- extract_zernike_opd.py: Parabola-based OPD with focal length

Key finding: OPD method gives 8-11% higher WFE values than Standard method
(more conservative/accurate for surfaces with lateral displacement under gravity)

Documentation updates:
- SYS_12: Added E22 ZernikeOPD as recommended method
- SYS_16: Added ZernikeDashboard, updated ZernikeWFE with OPD features
- Cheatsheet: Added Zernike method comparison table

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude/skills/core/study-creation-core.md

@@ -103,6 +103,55 @@ study_info = introspect_study(study_dir)
 
 ---
 
+## README Hierarchy (Parent-Child Documentation)
+
+Studies use a **two-level documentation system**:
+
+### Parent README (Geometry-Level)
+
+Location: `studies/{geometry_type}/README.md`
+
+Contains project-wide context that ALL sub-studies share:
+- Project overview (what is this component?)
+- Physical system specs (material, mass, loading)
+- Domain-specific specs (optical prescription for mirrors, structural limits for brackets)
+- Complete design variables catalog with ranges
+- Complete objectives catalog with formulas
+- Campaign history (evolution across sub-studies)
+- Sub-studies index with links and status
+
+**Example**: `studies/M1_Mirror/README.md`
+
+### Child README (Study-Level)
+
+Location: `studies/{geometry_type}/{study_name}/README.md`
+
+Contains study-specific details, references parent for context:
+```markdown
+# Study Name
+
+> **Parent Documentation**: See [../README.md](../README.md) for project overview and specifications.
+
+## Study Focus
+What THIS study specifically optimizes...
+```
+
+Contents:
+- Parent reference banner (MANDATORY first line)
+- Study focus (what differentiates this study)
+- Active variables (which params enabled)
+- Algorithm config (sampler, trials, settings)
+- Baseline/seeding (starting point)
+- Results summary
+
+### When Creating a Study
+
+1. **First study for geometry type** → Create BOTH parent and child READMEs
+2. **Subsequent studies** → Create child README, update parent's sub-studies index
+3. **New geometry type** → Create new `studies/{type}/` folder with parent README
+
+---
+
 ## PR.3 NXSolver Interface
 
 **Module**: `optimization_engine.nx_solver`