feat(location): add one-time current location detection

[Orinks]

Summary

• Add an opt-in one-time current-location detector with native Windows/macOS providers and graceful unsupported/denied/timeout results.
• Add "Use my current location" actions to add-location and edit-location dialogs while preserving manual search and editable saved-location labels.
• Add macOS location permission metadata, platform-scoped native location dependencies, changelog coverage, and focused tests.
• Make one Windows single-instance fallback test hermetic so live IPC state does not break the full suite.

Verification

• ..venv\Scripts\python.exe -m ruff check .
• ..venv\Scripts\pyright.exe src\accessiweather\current_location.py
• ..venv\Scripts\python.exe -m pytest tests\test_current_location.py tests\test_zone_enrichment_service.py tests\test_all_locations_view.py::TestEditLocation tests\test_config_manager.py::TestConfigManager tests\test_nuitka_build.py::test_macos_nuitka_command_uses_app_mode -q
• ..venv\Scripts\python.exe -m pytest -n auto -v --tb=short