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+**English** · [Dansk](Development-da) · [Bahasa Malaysia](Development-ms)
+
+# Development
+
+## Layout
+
+| Folder | Holds |
+| --- | --- |
+| `src/password_manager/domain` | Entry, password generator and errors; no input or output |
+| `src/password_manager/application` | Use cases and the repository port |
+| `src/password_manager/infrastructure` | The JSON repository |
+| `src/password_manager/presentation` | The MVVM view and view model |
+| `src/password_manager/constants.py` | Every constant and message |
+| `tests/` | `unit`, `integration` and `e2e` tests |
+| `tools/` | `capture_screenshots.py` |
+
+Imports point inward; only `main.py` connects the layers.
+
+## Tests and lint
+
+```bash
+python -m pytest
+python -m ruff format src tests tools
+python -m ruff check src tests tools
+```
+
+## Source documentation
+
+Comments are Doxygen style. Build the HTML with `doxygen Doxyfile`; it opens at
+`docs/doxygen/html/index.html`.
+
+## Screenshots
+
+On Windows, with the virtual environment active:
+
+```bash
+python tools/capture_screenshots.py
+```
+
+The images are written to `docs/images/` from the real window and a temporary
+data file.
+
+## Project documents
+
+The project follows a planning-first workflow: Business Case, Stakeholder
+Analysis, Project Plan and milestones are in `docs/`. Work is done on one branch
+and one pull request per milestone.