- Replace rmp-serde with bincode 1.x in Cargo.toml
- Update store.rs serialization/deserialization and ID hashing
- Rename model.rs helpers from to_msgpack/from_msgpack to to_bytes/from_bytes
- Consolidate MsgPack/MsgPackDecode error variants into single Bincode variant
- Remove skip_serializing_if on ssh_signature (incompatible with bincode)
- Update all documentation to reflect bincode storage format
