pack_backup / unpack_backup ship the magic header, format version,
Argon2id KDF, XChaCha20-Poly1305 AEAD, and zstd-compressed JSON
envelope. Empty-vault round-trip is the foundation; later tasks
add items, attachments, image, and git history.
Renames crate directories and sweeps identifiers so Plan 1B can reference
the post-rename names throughout.
- git mv crates/idfoto-{core,cli,wasm} → crates/relicario-{core,cli,wasm}
- sed sweep: idfoto_core/idfoto-core/IdfotoError/IDFOTO_IMAGE/.idfoto/ etc.
- All 128 relicario-core tests pass post-sweep
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
