DSO compatibility on windows

[DSchreyer]

Summary

This PR improves Windows compatibility while preserving POSIX behavior (#152):

• dso compile-config now emits backslashes for !path entries in params.yaml on Windows, and forward slashes on POSIX.
• DSO_TEMPLATE_LIBRARIES supports absolute Windows paths with drive letters (no accidental split on C:).
• Template rendering writes UTF-8 with LF line endings and a final newline to satisfy pre-commit checks.
• find_in_parent no longer recurses past Windows drive/UNC roots.

Rationale

Windows users encountered:

• Compiled params.yaml using forward slashes.
• pre-commit failures due to mixed line endings in generated files.
• Occasional RecursionError when searching above drive roots.
• Inability to include absolute Windows paths in DSO_TEMPLATE_LIBRARIES.

Changes

• src/dso/_compile_config.py
  Normalize compiled !path strings to OS-native separators for both relative and absolute cases.
• src/dso/_templates.py
  • Windows-aware parsing of DSO_TEMPLATE_LIBRARIES that tolerates X:\... entries.
  • _copy_with_render writes files with encoding="utf-8", LF newlines, and a trailing newline.
• src/dso/_util.py
  Robust root detection in _find_in_parent_abs: stops at drive/UNC roots; safe recurse barrier checks.
• Tests
  • tests/test_compile_config.py updated to normalize expectations with os.path.normpath and use UTF-8 I/O.
  • Related tests adjusted where needed to avoid hard-coding /.

Backward Compatibility

• On Windows, params.yaml now contains backslashes for compiled !path entries. Most consumers already accept native separators; if custom tooling expects /, normalize via pathlib/os.path.
• No CLI/API changes; POSIX behavior unchanged.

Testing

• Unit tests updated for cross-platform path expectations and UTF-8 I/O.
• Verified locally:
  • Windows: tests pass; no mixed line-ending failures; no recursion errors.
  • Linux/macOS: unchanged behavior; tests remain green.

Disclaimer

Some changes have been suggested by GPT-5 and Github Copilot. Therefore, some code might not follow best-practices or can lead to issues in specific circumstances. All tests have been passed on windows, but now also need to be passed on linux.

[DSchreyer]

Let's wait and see which CI fails

[DSchreyer]

Even though most checks pass, get-config does not work and I am unsure about the watermarking feature. I need to further investigate

[DSchreyer]

dso get-config now seems to be working as expected on windows

[DSchreyer]

Yeah, despite passing all errors there are issues now with this version on linux. dso compile-config outputs an invalid cross-device link error. Will be investigated, but no review is needed for now