feat(sphere): integrate generalized primitives from core/samplers

- compute.rs: Re-export text primitives from thrml_core::text
  (RollingHash, ngram_hashes, jaccard_similarity, TextSimilarityConfig)
- evaluation.rs: Document availability of thrml_core::metrics
  for general-purpose retrieval metrics
- lib.rs: Re-export generalized APIs for sphere users:
  - thrml_core::metrics: evaluate_retrieval, RetrievalMetrics
  - thrml_core::text: ngram_hashes, RollingHash, TextSimilarityConfig
  - thrml_samplers::maxcut: maxcut_gibbs, maxcut_multistart, cut_value

Sphere retains its domain-specific implementations (NavigationMetrics,
cpu_ising, substring) while exposing lower-level primitives for users
who need them.

Also fixes: duplicate GpuInfo re-export in thrml-core/src/lib.rs

Author: SashimiSaketoro

crates/thrml-core/src/lib.rs

@@ -95,10 +95,6 @@ pub use text::*;
 #[cfg(feature = "gpu")]
 pub use backend::GpuInfo;
 
-// Re-export GpuInfo only when gpu feature is enabled
-#[cfg(feature = "gpu")]
-pub use backend::GpuInfo;
-
 #[cfg(feature = "gpu")]
 pub use distance::*;
 #[cfg(feature = "gpu")]

crates/thrml-sphere/src/compute.rs

@@ -6,6 +6,16 @@
 //! - [`substring`]: Substring similarity for Ising max-cut coupling
 //! - [`cpu_ising`]: CPU-based f64 Ising max-cut partitioning
 //!
+//! ## Core Primitives
+//!
+//! For lower-level text similarity, see [`thrml_core::text`]:
+//! - `RollingHash`: Efficient n-gram hashing
+//! - `ngram_hashes`, `jaccard_similarity`: Text similarity primitives
+//!
+//! For simpler max-cut on dense matrices, see [`thrml_samplers::maxcut`]:
+//! - `maxcut_gibbs`, `maxcut_multistart`: Graph partitioning
+//! - `cut_value`: Compute cut quality
+//!
 //! ## Usage
 //!
 //! ```rust,ignore
@@ -23,6 +33,11 @@
 // Re-export core compute types from thrml-core
 pub use thrml_core::compute::{ComputeBackend, HybridConfig, OpType, PrecisionMode};
 
+// Re-export text similarity primitives from thrml-core
+pub use thrml_core::text::{
+    jaccard_similarity as text_jaccard, ngram_hashes, RollingHash, TextSimilarityConfig,
+};
+
 // =============================================================================
 // Substring Similarity (for Ising max-cut enhancement)
 // =============================================================================

crates/thrml-sphere/src/evaluation.rs

@@ -7,6 +7,14 @@
 //! - **MRR**: Mean Reciprocal Rank - average of 1/rank for correct answers
 //! - **nDCG@k**: Normalized Discounted Cumulative Gain
 //!
+//! ## Core Primitives
+//!
+//! For general-purpose retrieval metrics without navigation dependencies,
+//! see [`thrml_core::metrics`]:
+//! - `recall_at_k`, `mrr`, `ndcg`: Single-query metrics
+//! - `evaluate_retrieval`: Batch evaluation over multiple queries
+//! - `RetrievalMetrics`: Aggregated metrics struct
+//!
 //! ## Quick Start
 //!
 //! ```rust,ignore

crates/thrml-sphere/src/lib.rs

@@ -321,3 +321,9 @@ pub use compute::substring::SubstringConfig;
 
 // Re-export hardware tier types from thrml-core for RuntimeConfig users
 pub use thrml_core::compute::{HardwareTier, PrecisionProfile, RuntimePolicy};
+
+// Re-export generalized primitives from thrml-core and thrml-samplers
+// These can be used directly or as building blocks for sphere-specific APIs
+pub use thrml_core::metrics::{evaluate_retrieval, RetrievalMetrics};
+pub use thrml_core::text::{ngram_hashes, RollingHash, TextSimilarityConfig};
+pub use thrml_samplers::maxcut::{cut_value, maxcut_gibbs, maxcut_multistart};