Function compute_cache_namespace 

pub fn compute_cache_namespace(
    max_segment_tokens: usize,
    context_tokens: usize,
    profile: &str,
    batch_enabled: bool,
    prompt_version: &str,
) -> String

Compute a cache namespace that scopes lookups to a single set of schema and segmentation parameters. Cached rows from a different namespace are not eligible for reuse.