style: apply rustfmt across all crates and demos

Consistent formatting pass: line wrapping, import sorting, trailing
whitespace removal, let-chain indentation, merged derive attributes,
and unsafe block reformatting.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

demos/rtx-cellatlas-demo/src/cell_transformer.rs

@@ -3,7 +3,6 @@
 //! Implements a transformer-based model for learning cell representations
 //! from sparse gene expression data.
 
-
 /// Configuration for the Cell Transformer.
 #[derive(Debug, Clone)]
 pub struct CellTransformerConfig {
@@ -53,7 +52,7 @@ pub struct CellTransformer {
 
 impl CellTransformer {
     /// Create a new Cell Transformer with random initialization.
-    #[must_use] 
+    #[must_use]
     pub fn new(config: CellTransformerConfig) -> Self {
         use rand::SeedableRng;
         use rand_distr::{Distribution, Normal};
@@ -89,7 +88,7 @@ impl CellTransformer {
     }
 
     /// Encode a batch of cells into embeddings.
-    #[must_use] 
+    #[must_use]
     pub fn encode(&self, gene_indices: &[Vec<usize>], values: &[Vec<f32>]) -> Vec<Vec<f32>> {
         let batch_size = gene_indices.len();
         let mut embeddings = Vec::with_capacity(batch_size);
@@ -132,7 +131,7 @@ impl CellTransformer {
     }
 
     /// Get the hidden dimension.
-    #[must_use] 
+    #[must_use]
     pub fn hidden_dim(&self) -> usize {
         self.config.hidden_dim
     }