refactor: Engine updates and NX hooks improvements

optimization_engine:
- Updated nx_solver.py with improvements
- Enhanced solve_simulation.py
- Updated extractors/__init__.py
- Improved NX CAD hooks (expression_manager, feature_manager,
  geometry_query, model_introspection, part_manager)
- Enhanced NX CAE solver_manager hook

Documentation:
- Updated OP_01_CREATE_STUDY.md protocol
- Updated SYS_12_EXTRACTOR_LIBRARY.md

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

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

optimization_engine/hooks/nx_cad/expression_manager.py

@@ -36,11 +36,15 @@ import tempfile
 from pathlib import Path
 from typing import Optional, Dict, Any, List, Tuple, Union
 
-# NX installation path (configurable)
-NX_BIN_PATH = os.environ.get(
-    "NX_BIN_PATH",
-    r"C:\Program Files\Siemens\NX2506\NXBIN"
-)
+# Import NX path from centralized config
+try:
+    from config import NX_BIN_DIR
+    NX_BIN_PATH = str(NX_BIN_DIR)
+except ImportError:
+    NX_BIN_PATH = os.environ.get(
+        "NX_BIN_PATH",
+        r"C:\Program Files\Siemens\DesigncenterNX2512\NXBIN"
+    )
 
 # Journal template for expression operations
 EXPRESSION_OPERATIONS_JOURNAL = '''