Merge upstream/main into pr/upstream-model-tracking

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/internal/repository/usage_log_repo.go

@@ -3089,6 +3089,41 @@ func (r *usageLogRepository) GetUserBreakdownStats(ctx context.Context, startTim
 	return results, nil
 }
 
+// GetAllGroupUsageSummary returns today's and cumulative actual_cost for every group.
+// todayStart is the start-of-day in the caller's timezone (UTC-based).
+// TODO(perf): This query scans ALL usage_logs rows for total_cost aggregation.
+// When usage_logs exceeds ~1M rows, consider adding a short-lived cache (30s)
+// or a materialized view / pre-aggregation table for cumulative costs.
+func (r *usageLogRepository) GetAllGroupUsageSummary(ctx context.Context, todayStart time.Time) ([]usagestats.GroupUsageSummary, error) {
+	query := `
+		SELECT
+			g.id AS group_id,
+			COALESCE(SUM(ul.actual_cost), 0) AS total_cost,
+			COALESCE(SUM(CASE WHEN ul.created_at >= $1 THEN ul.actual_cost ELSE 0 END), 0) AS today_cost
+		FROM groups g
+		LEFT JOIN usage_logs ul ON ul.group_id = g.id
+		GROUP BY g.id
+	`
+
+	rows, err := r.sql.QueryContext(ctx, query, todayStart)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = rows.Close() }()
+	var results []usagestats.GroupUsageSummary
+	for rows.Next() {
+		var row usagestats.GroupUsageSummary
+		if err := rows.Scan(&row.GroupID, &row.TotalCost, &row.TodayCost); err != nil {
+			return nil, err
+		}
+		results = append(results, row)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return results, nil
+}
+
 // resolveModelDimensionExpression maps model source type to a safe SQL expression.
 func resolveModelDimensionExpression(modelType string) string {
 	switch usagestats.NormalizeModelSource(modelType) {