Function render_evidence 

pub fn render_evidence(e: &Evidence) -> String

Format a single Evidence item as one line of human-readable text.

This is also the input to crate::llm_prompt::sanitize_for_prompt: the prompt renderers call render_evidence then sanitize the result. Keeping a single rendering path means a wording change to evidence surfaces consistently in both human and prompt output.

Pure: no I/O, deterministic for any input variant.