r-efi 6.0.0 - license material provenance

Declared license: MIT OR Apache-2.0 OR LGPL-2.1-or-later

The published crate ships no LICENSE file. A verbatim license header extracted from src/lib.rs is included as LICENSE-HEADER.txt when present; canonical full texts are added so the distribution carries usable text. Marked declared-only, not upstream-collected.
