enable runtime compaction tracking and refresh compaction config docs

pkg/agent/loop.go

@@ -833,10 +833,11 @@ func alSessionListForTool(sm *session.SessionManager, limit int) []tools.Session
 	out := make([]tools.SessionInfo, 0, len(items))
 	for _, s := range items {
 		out = append(out, tools.SessionInfo{
-			Key:       s.Key,
-			Kind:      s.Kind,
-			Summary:   s.Summary,
-			UpdatedAt: s.Updated,
+			Key:             s.Key,
+			Kind:            s.Kind,
+			Summary:         s.Summary,
+			CompactionCount: s.CompactionCount,
+			UpdatedAt:       s.Updated,
 		})
 	}
 	return out

pkg/tools/sessions_tool.go

@@ -11,10 +11,11 @@ import (
 )
 
 type SessionInfo struct {
-	Key       string
-	Kind      string
-	Summary   string
-	UpdatedAt time.Time
+	Key             string
+	Kind            string
+	Summary         string
+	CompactionCount int
+	UpdatedAt       time.Time
 }
 
 type SessionsTool struct {
@@ -152,7 +153,7 @@ func (t *SessionsTool) Execute(ctx context.Context, args map[string]interface{})
 		var sb strings.Builder
 		sb.WriteString("Sessions:\n")
 		for _, s := range items {
-			sb.WriteString(fmt.Sprintf("- %s kind=%s updated=%s\n", s.Key, s.Kind, s.UpdatedAt.Format(time.RFC3339)))
+			sb.WriteString(fmt.Sprintf("- %s kind=%s compactions=%d updated=%s\n", s.Key, s.Kind, s.CompactionCount, s.UpdatedAt.Format(time.RFC3339)))
 		}
 		return strings.TrimSpace(sb.String()), nil
 	case "history":