feat: Add NXOpen Python intellisense integration

Implemented NXOpen Python stub file integration for intelligent code completion
in VSCode, significantly improving development workflow for NXOpen API usage.

Features Added:
- VSCode configuration for Pylance with NXOpen stub files
- Test script to verify intellisense functionality
- Comprehensive setup documentation with examples
- Updated development guidance with completed milestone

Configuration:
- Stub path: C:\Program Files\Siemens\Simcenter3D_2412\ugopen\pythonStubs
- Type checking mode: basic (balances help vs. false positives)
- Covers all NXOpen modules: Session, Part, CAE, Assemblies, etc.

Benefits:
- Autocomplete for NXOpen classes, methods, and properties
- Inline documentation and parameter type hints
- Faster development with reduced API lookup time
- Better LLM-assisted coding with visible API structure
- Catch type errors before runtime

Files:
- .vscode/settings.json - VSCode Pylance configuration
- tests/test_nxopen_intellisense.py - Verification test script
- docs/NXOPEN_INTELLISENSE_SETUP.md - Complete setup guide
- DEVELOPMENT_GUIDANCE.md - Updated with completion status

Testing:
- Stub files verified in NX 2412 installation
- Test script created with comprehensive examples
- Documentation includes troubleshooting guide

Next Steps:
- Research authenticated Siemens documentation access
- Investigate documentation scraping for LLM knowledge base
- Enable LLM to reference NXOpen API during code generation

This is Step 1 of NXOpen integration strategy outlined in DEVELOPMENT_GUIDANCE.md.

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

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

tests/test_nxopen_intellisense.py

@@ -0,0 +1,61 @@
+"""
+Test script to verify NXOpen Python intellisense is working with stub files.
+
+This script is NOT meant to be executed - it's for testing IDE code completion.
+Open this file in VSCode and verify that:
+1. Import statements show autocomplete suggestions
+2. NXOpen classes show available methods/properties
+3. Method parameters show type hints
+4. Hovering over objects shows documentation
+
+Setup Required:
+- VSCode with Pylance extension installed
+- .vscode/settings.json configured with stub path:
+  "python.analysis.stubPath": "C:\\Program Files\\Siemens\\Simcenter3D_2412\\ugopen\\pythonStubs"
+"""
+
+# Test 1: Import autocomplete
+# Type "import NXOpen." and verify you see module suggestions:
+# NXOpen.Part, NXOpen.Session, NXOpen.CAE, NXOpen.Assemblies, etc.
+import NXOpen
+import NXOpen.Part
+import NXOpen.Session
+import NXOpen.CAE
+import NXOpen.Assemblies
+
+# Test 2: Session object autocomplete
+# Type "session." and verify you see methods like GetSession(), Parts, etc.
+session = NXOpen.Session.GetSession()
+
+# Test 3: Part methods autocomplete
+# Type "part." and verify you see methods
+work_part = session.Parts.Work
+
+# Test 4: Expression methods autocomplete
+# Type "expression." and verify you see methods like FindObject, CreateExpression, etc.
+if work_part:
+    expressions = work_part.Expressions
+    # Type "expressions." and verify methods appear:
+    # expressions.FindObject, CreateExpression, EditWithUnits, etc.
+
+    # Test 5: Parameter type hints
+    # Hover over CreateExpression and verify you see parameter types
+    # expression = expressions.CreateExpression("test", "1.0")
+
+# Test 6: CAE autocomplete
+# Type "fem_part." and verify CAE-specific methods appear
+fem_part = NXOpen.CAE.FemPart
+# Type "fem_part." to see: BaseFemPart, FemModel, etc.
+
+# Test 7: Assembly autocomplete
+# Type "assemblies." and verify assembly methods appear
+assemblies = work_part.ComponentAssembly if work_part else None
+# Type "assemblies." to see: AddComponent, CreateComponent, etc.
+
+# Test 8: Documentation tooltips
+# Hover over any NXOpen class/method and verify documentation appears
+# Example: Hover over "GetSession()" above - should show docstring
+
+print("Intellisense test file - Do not execute!")
+print("Open in VSCode and test autocomplete functionality")
+print("If you see type hints and autocomplete suggestions, intellisense is working!")