2c45a6fb3e3144f7169df719dea76c1dc7ad7fa9
Cover expand_tilde (bare ~, ~/sub, absolute, relative, non-leading tilde, ~user, whitespace) and validate_custom_path (empty/whitespace, missing, existing file vs dir via CARGO_MANIFEST_DIR, tilde-prefixed missing). Test-only; no production code or dependency changes. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>