Issue #1: idmap target now uses parent+name (overlays_workshop instead of
workshop) to prevent basename collisions across allowlist roots; explicit
die() on collision detected in the loop.
Issue #2: env-var uid stubs (renamed to LEFT4ME_TEST_SANDBOX_UID etc.) are
only honoured when LEFT4ME_OVERLAY_PRINT_ONLY=1, so a misconfigured systemd
unit override cannot influence real uid mapping.
Issue #3: os.stat(lowerdir) is wrapped in try/except OSError with a die()
that shell-quotes the path and includes the exception, matching the helper's
existing error style.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
90531864b3