docs: Update protocol docs and method selector improvements

- SYS_12: Add extractor library updates
- SYS_15: Add method selector documentation updates
- method_selector.py: Minor improvements to method selection logic

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

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

docs/protocols/system/SYS_12_EXTRACTOR_LIBRARY.md

@@ -371,9 +371,33 @@ If needed physics isn't in library:
 |---------|-------|----------|
 | "No displacement data found" | Wrong subcase number | Check subcase in OP2 |
 | "OP2 file not found" | Solve failed | Check NX logs |
-| "Element type not supported" | Using unsupported element | Check available types in function |
+| "Unknown element type: auto" | Element type not specified | Specify `element_type='cquad4'` or `'ctetra'` |
+| "No stress results in OP2" | Wrong element type specified | Use correct type for your mesh |
 | Import error | Module not exported | Check `__init__.py` exports |
 
+### Element Type Selection Guide
+
+**Critical**: You must specify the correct element type for stress extraction based on your mesh:
+
+| Mesh Type | Elements | `element_type=` |
+|-----------|----------|-----------------|
+| **Shell** (thin structures) | CQUAD4, CTRIA3 | `'cquad4'` or `'ctria3'` |
+| **Solid** (3D volumes) | CTETRA, CHEXA | `'ctetra'` or `'chexa'` |
+
+**How to check your mesh type:**
+1. Open .dat/.bdf file
+2. Search for element cards (CQUAD4, CTETRA, etc.)
+3. Use the dominant element type
+
+**Common models:**
+- **Bracket (solid)**: Uses CTETRA → `element_type='ctetra'`
+- **Beam (shell)**: Uses CQUAD4 → `element_type='cquad4'`
+- **Mirror (shell)**: Uses CQUAD4 → `element_type='cquad4'`
+
+**Von Mises column mapping** (handled automatically):
+- Shell elements (8 columns): von Mises at column 7
+- Solid elements (10 columns): von Mises at column 9
+
 ---
 
 ## Cross-References
@@ -583,3 +607,4 @@ nx_journals/
 | 1.0 | 2025-12-05 | Initial consolidation from scattered docs |
 | 1.1 | 2025-12-06 | Added Phase 2: E12 (principal stress), E13 (strain energy), E14 (SPC forces) |
 | 1.2 | 2025-12-06 | Added Phase 3: E15-E17 (thermal), E18 (modal mass) |
+| 1.3 | 2025-12-07 | Added Element Type Selection Guide; documented shell vs solid stress columns |

docs/protocols/system/SYS_15_METHOD_SELECTOR.md

@@ -385,6 +385,25 @@ if user_confirms:
 | PURE_FEA recommended | High dimensionality | Consider dimension reduction |
 | GNN_FIELD recommended | Need field visualization | Set up atomizer-field |
 
+### Config Format Compatibility
+
+The method selector supports multiple config JSON formats:
+
+| Old Format | New Format | Both Supported |
+|------------|------------|----------------|
+| `parameter` | `name` | Variable name |
+| `bounds: [min, max]` | `min`, `max` | Variable bounds |
+| `goal` | `direction` | Objective direction |
+
+**Example equivalent configs:**
+```json
+// Old format (UAV study style)
+{"design_variables": [{"parameter": "angle", "bounds": [30, 60]}]}
+
+// New format (beam study style)
+{"design_variables": [{"name": "angle", "min": 30, "max": 60}]}
+```
+
 ---
 
 ## Cross-References
@@ -418,5 +437,6 @@ optimization_engine/
 
 | Version | Date | Changes |
 |---------|------|---------|
+| 2.1 | 2025-12-07 | Added config format flexibility (parameter/name, bounds/min-max, goal/direction) |
 | 2.0 | 2025-12-07 | Added NNQualityAssessor with relative accuracy thresholds |
 | 1.0 | 2025-12-06 | Initial implementation with 4 methods |

optimization_engine/method_selector.py

@@ -486,12 +486,17 @@ class ProblemProfiler:
         # Extract design variables
         design_vars = config.get('design_variables', [])
         profile.n_variables = len(design_vars)
-        profile.variable_names = [v['parameter'] for v in design_vars]
+        # Support both 'parameter' and 'name' keys for variable naming
+        profile.variable_names = [v.get('parameter') or v.get('name') for v in design_vars]
 
         volume = 1.0
         for var in design_vars:
-            name = var['parameter']
+            name = var.get('parameter') or var.get('name')
-            bounds = var.get('bounds', [0, 1])
+            # Support both 'bounds' array and 'min'/'max' fields
+            if 'bounds' in var:
+                bounds = var['bounds']
+            else:
+                bounds = [var.get('min', 0), var.get('max', 1)]
             profile.variable_bounds[name] = (bounds[0], bounds[1])
             profile.variable_types[name] = var.get('type', 'continuous')
             volume *= (bounds[1] - bounds[0])
@@ -501,7 +506,11 @@ class ProblemProfiler:
         objectives = config.get('objectives', [])
         profile.n_objectives = len(objectives)
         profile.objective_names = [o['name'] for o in objectives]
-        profile.objective_goals = {o['name']: o.get('goal', 'minimize') for o in objectives}
+        # Support both 'goal' and 'direction' keys for objective direction
+        profile.objective_goals = {
+            o['name']: o.get('goal') or o.get('direction', 'minimize')
+            for o in objectives
+        }
         profile.is_multi_objective = profile.n_objectives > 1
 
         # Extract constraints