rustdoc_processor 0.1.0

Compute, cache, index, and query rustdoc JSON documentation for crates in a project's dependency graph.

The pipeline:

1. Compute ([compute::compute_crate_docs]): invoke cargo rustdoc to generate JSON docs.
2. Cache ([cache::RustdocGlobalFsCache]): persist raw docs and secondary indexes in a SQLite database at {cache_dir}/{fingerprint}.db.
3. Index ([indexing]): build secondary indexes — import paths, item lookups, and external re-export tracking.
4. Query ([queries::Crate], [CrateCollection]): look up items by path, resolve cross-crate references, and retrieve canonical import paths.