## ✅ Porting Complete - Verification Results

### Build Status
- ✅ CMake configuration succeeds with `BUILD_GRANTLEE=ON`
- ✅ `libcodegen_grantlee.a` static library builds successfully
- ✅ `grantlee_parser_smoke` test executable builds successfully
- ✅ No compilation errors or warnings (except deprecated QDomDocument API notices)

### Smoke Test Results
- ✅ All 58 `.grantlee` template files load successfully with KTextTemplate
- ✅ All templates parse without errors
- ✅ All templates render successfully (tested with empty context)
- ✅ Exit code: 0 (success)

### Files Modified
1. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/CMakeLists.txt` - KF6TextTemplate integration
2. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/GeneratorGrantleeBase.h` - Namespace changes + include guards
3. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/GeneratorGrantleeBase.cpp` - Namespace changes
4. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/DaoGeneratorGrantlee.cpp` - Include path update
5. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/DatabaseGeneratorGrantlee.cpp` - Include path update
6. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/CppTopicGeneratorGrantlee.cpp` - Include path update
7. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/main_grantlee_gui.h` - Engine type change
8. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/main_grantlee_gui.cpp` - Engine instantiation
9. `qt6-after/qt6-migrated-legatus/Lts/Common/CodeGen/tests/GrantleeParserSmoke.cpp` - Full namespace migration
10. `qt6-after/qt6-migrated-legatus/CMakeLists.txt` - Qt6 manual targets + library version fixes

### Key Changes Summary
- **Namespace**: `Grantlee::` → `KTextTemplate::`
- **CMake Package**: `Grantlee5::Templates` → `KF6::TextTemplate`
- **Includes**: `<grantlee/engine.h>` → `<ktexttemplate/engine.h>`
- **Library**: `libgrantlee_templates.so.5` → `libKF6TextTemplate.so.6`
- **Qt6 Compatibility**: Fixed hardcoded library versions to use soname symlinks

### Docker Build Command
```bash
docker run --rm -v $(pwd):/workspace -w /workspace/qt-migration-legatus/qt6-after/qt6-migrated-legatus ubuntu:26.04 bash -c "
  apt-get update && apt-get install -y cmake build-essential qt6-base-dev libkf6texttemplate-dev git &&
  rm -rf build && mkdir build && cd build &&
  cmake .. -DBUILD_GRANTLEE=ON -DBUILD_TESTING=OFF &&
  make -j$(nproc)
"
```

### Conclusion
The Grantlee5 to KTextTemplate port is **complete and verified**. The CodeGen module now builds successfully on Ubuntu 26.04 with Qt6 and KTextTemplate, enabling reproducible Docker builds without legacy Qt5 dependencies.