feat(query): include session totals and stable framework names

internal/store/postgres/sessions.go

@@ -89,7 +89,7 @@ func (d *DB) ListSessions(ctx context.Context, f SessionsFilter) ([]SessionRow,
 				session_id,
 				MIN(ts) as started_at,
 				MAX(CASE WHEN type = 'session.end' THEN ts END) as ended_at,
-				MAX(source_framework) as framework,
+				COALESCE((ARRAY_AGG(source_framework ORDER BY CASE WHEN type = 'session.start' THEN 0 ELSE 1 END, ts) FILTER (WHERE source_framework IS NOT NULL))[1], 'unknown') as framework,
 				MAX(client_id) as client_id,
 				MAX(payload->'event'->'source'->>'host') as host,
 				COUNT(DISTINCT run_id) as run_count
@@ -136,3 +136,59 @@ func (d *DB) ListSessions(ctx context.Context, f SessionsFilter) ([]SessionRow,
 
 	return out, nextCursor, rows.Err()
 }
+
+// CountSessions returns the total number of sessions matching the filter (without limit or cursor).
+func (d *DB) CountSessions(ctx context.Context, f SessionsFilter) (int, error) {
+	var innerConditions []string
+	var outerConditions []string
+	var args []any
+	argN := 1
+
+	if f.From == nil {
+		t := time.Now().Add(-24 * time.Hour)
+		f.From = &t
+	}
+	innerConditions = append(innerConditions, fmt.Sprintf("ts >= $%d", argN))
+	args = append(args, *f.From)
+	argN++
+
+	if f.To != nil {
+		innerConditions = append(innerConditions, fmt.Sprintf("ts <= $%d", argN))
+		args = append(args, *f.To)
+		argN++
+	}
+
+	if f.Framework != "" {
+		innerConditions = append(innerConditions, fmt.Sprintf("source_framework = $%d", argN))
+		args = append(args, f.Framework)
+		argN++
+	}
+
+	if f.Host != "" {
+		outerConditions = append(outerConditions, fmt.Sprintf("host = $%d", argN))
+		args = append(args, f.Host)
+		argN++
+	}
+
+	innerWhere := strings.Join(innerConditions, " AND ")
+	outerWhere := ""
+	if len(outerConditions) > 0 {
+		outerWhere = "WHERE " + strings.Join(outerConditions, " AND ")
+	}
+
+	query := fmt.Sprintf(`
+		WITH session_groups AS (
+			SELECT
+				session_id,
+				MAX(payload->'event'->'source'->>'host') as host
+			FROM events
+			WHERE session_id IS NOT NULL AND %s
+			GROUP BY session_id
+		)
+		SELECT COUNT(*) FROM session_groups %s
+	`, innerWhere, outerWhere)
+
+	var count int
+	err := d.sql.QueryRowContext(ctx, query, args...).Scan(&count)
+	return count, err
+}