feat: Add M1 mirror Zernike optimization with correct RMS calculation

Major improvements to telescope mirror optimization workflow:

Assembly FEM Workflow (solve_simulation.py):
- Fixed multi-part assembly FEM update sequence
- Use ImportFromFile() for reliable expression updates
- Add DuplicateNodesCheckBuilder with MergeOccurrenceNodes=True
- Switch to Foreground solve mode for multi-subcase solutions
- Add detailed logging and diagnostics for node merge operations

Zernike RMS Calculation:
- CRITICAL FIX: Use correct surface-based RMS formula
  - Global RMS = sqrt(mean(W^2)) from actual WFE values
  - Filtered RMS = sqrt(mean(W_residual^2)) after removing low-order fit
  - This matches zernike_Post_Script_NX.py (optical standard)
- Previous WRONG formula was: sqrt(sum(coeffs^2))
- Add compute_rms_filter_j1to3() for optician workload metric

Subcase Mapping:
- Fix subcase mapping to match NX model:
  - Subcase 1 = 90 deg (polishing orientation)
  - Subcase 2 = 20 deg (reference)
  - Subcase 3 = 40 deg
  - Subcase 4 = 60 deg

New Study: M1 Mirror Zernike Optimization
- Full optimization config with 11 design variables
- 3 objectives: rel_filtered_rms_40_vs_20, rel_filtered_rms_60_vs_20, mfg_90_optician_workload
- Neural surrogate support for accelerated optimization

Documentation:
- Update ZERNIKE_INTEGRATION.md with correct RMS formula
- Update ASSEMBLY_FEM_WORKFLOW.md with expression import and node merge details
- Add reference scripts from original zernike_Post_Script_NX.py

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

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

optimization_engine/nx_solver.py

@@ -285,14 +285,11 @@ sys.argv = ['', {argv_str}]  # Set argv for the main function
         # Set up environment for Simcenter/NX
         env = os.environ.copy()
 
-        # Set license server (use 29000 for Simcenter)
-        # Override any incorrect license server settings
-        env['SPLM_LICENSE_SERVER'] = '29000@AntoineThinkpad'
-
-        # Force desktop licensing instead of enterprise
-        # User has nx_nas_bn_basic_dsk (desktop) not nx_nas_basic_ent (enterprise)
-        env['NXNA_LICENSE_FILE'] = '29000@AntoineThinkpad'
-        env['NXNASTRAN_LICENSE_FILE'] = '29000@AntoineThinkpad'
+        # Use existing SPLM_LICENSE_SERVER from environment if set
+        # Only set if not already defined (respects user's license configuration)
+        if 'SPLM_LICENSE_SERVER' not in env or not env['SPLM_LICENSE_SERVER']:
+            env['SPLM_LICENSE_SERVER'] = '29000@localhost'
+            print(f"[NX SOLVER] WARNING: SPLM_LICENSE_SERVER not set, using default: {env['SPLM_LICENSE_SERVER']}")
 
         # Add NX/Simcenter paths to environment
         nx_bin = self.nx_install_dir / "NXBIN"