feat: Add NX study models and optimization histories

Includes all study folders with NX models for development:
- bracket_stiffness_optimization (V1, V2, V3)
- drone_gimbal_arm_optimization
- simple_beam_optimization
- uav_arm_optimization (V1, V2)
- training_data_export_test
- uav_arm_atomizerfield_test

Contains .prt, .fem, .sim files and optimization databases.

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

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

studies/bracket_stiffness_optimization/optimization_config.json

@@ -0,0 +1,100 @@
+{
+  "study_name": "bracket_stiffness_optimization",
+  "description": "Maximize bracket stiffness while minimizing mass (constraint: mass ≤ 0.2 kg)",
+
+  "objectives": [
+    {
+      "name": "stiffness",
+      "type": "maximize",
+      "description": "Structural stiffness (N/mm) calculated as Force/Displacement",
+      "target": null,
+      "weight": 1.0
+    },
+    {
+      "name": "mass",
+      "type": "minimize",
+      "description": "Total mass (kg) - secondary objective with hard constraint",
+      "target": null,
+      "weight": 0.1
+    }
+  ],
+
+  "constraints": [
+    {
+      "name": "mass_limit",
+      "type": "less_than",
+      "value": 0.2,
+      "description": "Maximum allowable mass: 200 grams"
+    }
+  ],
+
+  "design_variables": [
+    {
+      "name": "support_angle",
+      "type": "continuous",
+      "min": 20.0,
+      "max": 70.0,
+      "initial": 60.0,
+      "unit": "degrees",
+      "description": "Angle of support arm relative to base"
+    },
+    {
+      "name": "tip_thickness",
+      "type": "continuous",
+      "min": 30.0,
+      "max": 60.0,
+      "initial": 30.0,
+      "unit": "mm",
+      "description": "Thickness of bracket tip where load is applied"
+    }
+  ],
+
+  "optimization_settings": {
+    "algorithm": "NSGA-II",
+    "n_trials": 50,
+    "n_jobs": 1,
+    "sampler": "TPESampler",
+    "pruner": "MedianPruner",
+    "pruner_settings": {
+      "n_startup_trials": 10,
+      "n_warmup_steps": 5,
+      "interval_steps": 1
+    },
+    "timeout": null,
+    "seed": 42
+  },
+
+  "simulation_settings": {
+    "solver": "NX_Nastran",
+    "solution_type": "SOL101",
+    "analysis_type": "Linear_Static",
+    "model_file": "1_setup/model/Bracket.prt",
+    "sim_file": "1_setup/model/Bracket_sim1.sim",
+    "fem_file": "1_setup/model/Bracket_fem1.fem"
+  },
+
+  "extraction_settings": {
+    "extractor_module": "bracket_stiffness_extractor",
+    "extractor_class": "BracketStiffnessExtractor",
+    "field_file": "export_field_dz.fld",
+    "op2_file": "Bracket_sim1.op2",
+    "force_component": "fz",
+    "displacement_component": "z",
+    "displacement_aggregation": "max_abs"
+  },
+
+  "output_settings": {
+    "results_dir": "2_results",
+    "database_name": "study.db",
+    "checkpoint_interval": 5,
+    "visualization": true,
+    "export_format": ["json", "csv", "parquet"]
+  },
+
+  "dashboard_settings": {
+    "enabled": true,
+    "port": 8000,
+    "realtime_updates": true,
+    "websocket": true
+  }
+}