Function cosine_similarity 

fn cosine_similarity(a: &[f32], b: &[f32]) -> f32

Calculates cosine similarity between two embedding vectors.

Returns a value in the range [0.0, 1.0] where:

• 1.0 = identical vectors
• 0.0 = orthogonal vectors

Panics

This function does not panic. If vectors have different lengths or zero magnitude, it returns 0.0 to indicate no similarity.