fix: render duplicate mirror modal values correctly

[yosofbadr]

Summary

Draft / waiting on latest CI.

Fixes #1331 by making the duplicate-entry mirror confirmation and progress text render stable, user-readable values.

The modal now lists duplicate entry paths instead of raw object representations, and the progress label receives the expected total value for translation formatting. The regression tests were updated to be portable across Windows path separators and translated CI locales.

Tasks Completed

• Platforms Tested:
  • Windows x86
  • Windows ARM
  • macOS x86
  • macOS ARM - targeted local test/lint
  • Linux x86
  • Linux ARM
    • GitHub Actions for the latest push are awaiting maintainer approval on the fork. Earlier CI failures were due to non-portable test expectations; the latest commit updates those tests.
• Tested For:
  • Basic functionality - targeted duplicate mirror modal regression tests
  • PyInstaller executable
    • Local: uv run --extra pytest python -m pytest tests/qt/test_mirror_entries_modal.py tests/macros/test_dupe_files.py -q
    • Local: uv run --extra ruff ruff check src/tagstudio/qt/mixed/mirror_entries_modal.py tests/qt/test_mirror_entries_modal.py
    • Missing before marking ready again: latest GitHub Actions run or maintainer acceptance of the local targeted coverage.

[yosofbadr]

Closing this after a stricter audit. The targeted tests pass locally, but the latest fork CI has not run and a full local pytest run still segfaults in the Qt/PySide stack on my machine. Given that this PR already had CI failures from my test assumptions, I do not want to leave it open without stronger validation.

Sorry for the noise.