In-memory providers are in diskann-providers/src/model/graph/provider/async_/inmem. Move them up to diskann-inmem crate.
Move traits and utilities in diskann-providers/src/model/graph/provider/async_/common.rs that are used solely by the in-mem providers to the inmem crate.
If you encounter further Rust orphan rule violations, list all the violations.

Mark is in the process of authoring an in-mem v2 replacement for our current in-mem implementation. Following it landing, the original in-mem implementation will need to be removed.