The command now supports reopening existing indexes instead of failing when the output file exists. Control flow branches between opening an existing index and constructing a new one, moving configuration setup exclusively to the creation path. Directory existence is enforced upfront with proper I/O error propagation. The --force flag retains its original semantics by removing the target directory before proceeding with a fresh build.
Introduces a Make-based orchestration for simulating, indexing, merging, filtering, and verifying k-mer counts and presence. Exposes internal builder and iterator APIs publicly, enforces mandatory leading slashes for predicate patterns, registers the `obitaxonomy` crate, and updates tooling configurations alongside documentation.