## ℹ️ Description
Core module for XDG Base Directory specification support.
- Link to the related issue(s): N/A (new feature)
- Adds portable and XDG installation mode path resolution
## 📋 Changes Summary
- New `xdg_paths.py` module with 11 path resolution functions
- Comprehensive test suite (32 tests, 95% coverage)
- German translations for all user-facing strings
- Moved `platformdirs` from dev to runtime dependencies
**Part 1 of 3 for XDG support**
- Depends on: None
- Preserves: extend command, ContactDefaults.location
### ⚙️ Type of Change
- [x] ✨ New feature (adds new functionality without breaking existing
usage)
## ✅ Checklist
- [x] I have reviewed my changes to ensure they meet the project's
standards.
- [x] I have tested my changes and ensured that all tests pass (`pdm run
test`).
- [x] I have formatted the code (`pdm run format`).
- [x] I have verified that linting passes (`pdm run lint`).
- [x] I have updated documentation where necessary.
By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added support for portable and XDG-standard installation modes for
flexible config, cache, and state storage.
* **Chores**
* Added a runtime dependency to handle platform-specific directory
locations.
* **Tests**
* Added comprehensive unit tests covering path resolution,
installation-mode detection, interactive prompts, and Unicode path
handling.
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
