Function temporal_analysis 

pub fn temporal_analysis(
    graph: &KnowledgeGraph,
    repo_root: &Path,
    top_n: usize,
) -> Vec<TemporalNode>

Analyze temporal risk by correlating graph nodes with git history.

For each node’s source file, queries git log to determine change frequency and recency. Risk score = churn_rate × normalized_degree.

Returns up to top_n nodes sorted by risk score descending.