feat(review): surface graph freshness metadata

Author: haasonsaas

TODO.md

@@ -66,7 +66,7 @@ This roadmap is derived from deep research into Greptile's public docs, blog, MC
 33. [ ] Add contract edges between interfaces, implementations, and API endpoints.
 34. [ ] Add "similar implementation" lookup so repeated patterns and divergences are explicit.
 35. [x] Add cross-file blast-radius summaries to findings when a change affects many callers.
-36. [ ] Add graph freshness/version metadata so reviews know whether they are using stale repository intelligence.
+36. [x] Add graph freshness/version metadata so reviews know whether they are using stale repository intelligence.
 37. [x] Add graph-backed ranking of related files before semantic RAG retrieval.
 38. [x] Add graph query traces to `dag_traces` or review artifacts for explainability and debugging.
 39. [x] Add graph-aware eval fixtures that require multi-hop code understanding to pass.

src/core/context_provenance.rs

@@ -12,6 +12,7 @@ pub enum ContextProvenance {
     CustomContextNotes,
     DependencyGraphNeighborhood,
     PathSpecificFocusAreas,
+    RepositoryGraphMetadata,
     PatternRepositoryContext {
         source: String,
     },
@@ -89,6 +90,7 @@ impl ContextProvenance {
             | Self::CustomContextNotes
             | Self::DependencyGraphNeighborhood
             | Self::PathSpecificFocusAreas
+            | Self::RepositoryGraphMetadata
             | Self::RelatedTestFile
             | Self::ReverseDependencySummary => 0,
         }
@@ -109,6 +111,7 @@ impl ContextProvenance {
             Self::CustomContextNotes => "custom context notes".to_string(),
             Self::DependencyGraphNeighborhood => "dependency graph neighborhood".to_string(),
             Self::PathSpecificFocusAreas => "path-specific focus areas".to_string(),
+            Self::RepositoryGraphMetadata => "repository graph metadata".to_string(),
             Self::PatternRepositoryContext { source } => {
                 format!("pattern repository: {source}")
             }
@@ -179,5 +182,9 @@ mod tests {
             ContextProvenance::pattern_repository_context("org/repo").to_string(),
             "pattern repository: org/repo"
         );
+        assert_eq!(
+            ContextProvenance::RepositoryGraphMetadata.to_string(),
+            "repository graph metadata"
+        );
     }
 }