Don't panic in `uv export --frozen` when the lockfile is outdated
Provide a good error message when the discovered workspace members mismatch with the locked workspace members in `uv export --frozen`, instead of panicking.
fix: resolve compilation issues in PermissionDenied test
- Replace non-existent uv_command! macro with context.pip_compile() pattern
- Add Unix PermissionsExt import for std::fs::Permissions::from_mode usage
- Fix test compilation errors that caused clippy and test failures