Function format_search 

pub fn format_search<S: GraphStore + ?Sized>(
    store: &S,
    branch: &str,
    query: &str,
    hits: Vec<SearchHit>,
    semantic_available: bool,
    budget_tokens: usize,
) -> Result<AgentSearchResponse>

Format ranked search hits as compact implementation evidence shared by CLI and MCP. Retrieval may be lexical-only or RRF hybrid; presentation is stable.