feat: custom IFC converter with C++ geometry injection

- Add custom IFC converter using web-ifc C++ DLL for geometry extraction
- Add GeometryInjector.cs: patches Speckle objects with mesh geometry
- Add NativeIfcGeometry.cs: P/Invoke bindings to WebIfcDll
- Add CustomMeshConverterFactory.cs: custom Xbim mesh converter
- Configure fileimport-service dotnet IFC pipeline
- Add VPS deployment config (docker-compose-vps.yml)
- Add dev scripts: run_backend.bat, run_frontend.bat, start_dev.bat
- Update .gitignore: exclude scratch/IFC-toolkit, engine_web-ifc
- Memory optimization for Xbim (MemoryModel mode)

start_dev.bat

@@ -0,0 +1,38 @@
+@echo off
+echo ============================================
+echo   SPECKLE SERVER DEV STARTUP
+echo ============================================
+echo.
+
+REM Set Node 22 first
+set "NVM_PATH=C:\Users\huanld\AppData\Local\nvm\v22.19.0"
+set "PATH=%NVM_PATH%;%PATH%"
+
+echo [1/2] Checking node version...
+node -v
+echo.
+
+REM First fix VPS - restart Keycloak via SSH  
+echo [VPS] Checking and restarting Keycloak on VPS...
+ssh -o StrictHostKeyChecking=no -i "%USERPROFILE%\.ssh\id_rsa" root@100.64.0.3 "cd /root && docker compose -f docker-compose-vps.yml up -d keycloak valkey 2>&1"
+echo.
+echo [VPS] Waiting 15 seconds for Keycloak to start...
+timeout /t 15 /nobreak
+echo.
+
+REM Start backend in new window
+echo [2/3] Starting Backend Server (port 3000)...
+start "Speckle Backend" cmd /k "set PATH=%NVM_PATH%;%PATH% && cd /d d:\speckle-server\packages\server && npx tsx --import ./esmLoader.js ./run.ts"
+timeout /t 3 /nobreak
+
+REM Start frontend in new window  
+echo [3/3] Starting Frontend (port 8081)...
+start "Speckle Frontend" cmd /k "set PATH=%NVM_PATH%;%PATH% && cd /d d:\speckle-server\packages\frontend-2 && npx nuxi dev"
+
+echo.
+echo ============================================
+echo  Servers starting in separate windows!
+echo  Backend:  http://127.0.0.1:3000
+echo  Frontend: http://127.0.0.1:8081
+echo ============================================
+pause