Module bytecode 

Bytecode layer — KeyCard ↔ canonical bytecode (pre-chunking).

Per design/SPEC_mk_v0_1.md §3 and bip/bip-mnemonic-key.mediawiki §“Bytecode layer”. The bytecode is the byte sequence emitted between the string-layer chunk header and the cross-chunk integrity hash; the string-layer (BCH, HRP-mixing, chunk reassembly) lives in crate::string_layer (Phase 5).

Submodules:

• header: 1-byte bytecode header (version + fingerprint flag)
• path: standard-table dictionary + 0xFE explicit-path codec
• xpub_compact: 73-byte compact xpub form with depth/child_number reconstruction from origin_path
• encode: top-level KeyCard → Vec<u8> encoder
• decode: top-level Vec<u8> → KeyCard decoder

Re-exports

pub use decode::decode_bytecode;

pub use encode::encode_bytecode;

pub use header::BytecodeHeader;

pub use path::STANDARD_PATHS;

pub use path::decode_path;

pub use path::encode_path;

pub use path::lookup_indicator;

pub use path::lookup_path;

pub use xpub_compact::XpubCompact;

pub use xpub_compact::decode_xpub_compact;

pub use xpub_compact::encode_xpub_compact;

pub use xpub_compact::reconstruct_xpub;

Modules

decode

Top-level bytecode decoder: canonical Vec<u8> → KeyCard.

encode

Top-level bytecode encoder: KeyCard → canonical Vec<u8>.

header

1-byte bytecode header — version + reserved + fingerprint flag.

path

Origin-path codec — standard-table dictionary + 0xFE explicit-path escape hatch.

xpub_compact

73-byte compact xpub form per design/SPEC_mk_v0_1.md §3.6 (closure Q-7).