Module mutation 

Columnar mutation engine: coordinates PK index, delete bitmaps, memtable, and WAL records for full INSERT/UPDATE/DELETE.

The MutationEngine is the single point of coordination for all columnar write operations. It produces WAL records that must be persisted before the mutation is considered durable.

Re-exports

pub use engine::MutationEngine;

pub use engine::MutationResult;

Modules

engine

MutationEngine struct, constructor, accessors, and shared helpers.

flush

Post-write coordination: memtable flush + compaction commit.

write

Write-path mutations: insert, insert_if_absent, delete, update.