Fix clippy warnings

Fixes empty line after doc comment warnings and other clippy issues
to prevent CI failures with -D warnings flag.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: 2 people

src/metrics.rs

@@ -14,7 +14,7 @@ pub fn compute_isotropy(embeddings: &[Vec<f32>]) -> f32 {
     }
 
     let n = embeddings.len();
-    let d = embeddings[0].len();
+    let _d = embeddings[0].len();
 
     if n < 2 {
         return 0.0;