Introduces a new `estimate` CLI subcommand to calculate bloom filter size, evidence bits, and false-positive rates for approximate indexing. Updates the index building and querying pipelines to support both exact and approximate evidence types via a unified `EvidenceKind` abstraction. Refactors `MphfLayer` and partition index builders to route operations based on the selected evidence mode, and adds the required `obilayeredmap` dependency.
Eric Coissac
876bc0127f