docs(rust): update documentation comments

- Simplify description in Engine::query_streaming to use "receiver that yields
  retrieval events" instead of detailed type reference
- Update error module documentation to use proper rustdoc syntax with
  `[@enum@Error]` for better documentation generation

Author: zTgx

rust/src/client/engine.rs

@@ -485,7 +485,7 @@ impl Engine {
 
     /// Query a document with streaming results.
     ///
-    /// Returns a [`RetrieveEventReceiver`] that yields [`RetrieveEvent`](crate::retrieval::RetrieveEvent)s
+    /// Returns a receiver that yields retrieval events
     /// as the retrieval pipeline progresses through each stage.
     ///
     /// Only supports single-document scope (via `with_doc_ids` with one ID).

rust/src/error.rs

@@ -4,7 +4,7 @@
 //! Error types for the vectorless library.
 //!
 //! This module provides a comprehensive error type hierarchy for all operations.
-//! All errors are consolidated into [`Error`] with specific variants for each category.
+//! All errors are consolidated into [`enum@Error`] with specific variants for each category.
 
 use thiserror::Error;