feat: aggregate journals across node subtrees

internal/core/activity/suggest.go

@@ -9,13 +9,14 @@ const (
 
 // SuggestionDetail is a lightweight event summary for suggestion display.
 type SuggestionDetail struct {
-	ID        string `json:"id"`
-	EventType string `json:"eventType"`
+	ID         string `json:"id"`
+	EventType  string `json:"eventType"`
 	TargetType string `json:"targetType"`
-	TargetID  string `json:"targetId"`
-	Title     string `json:"title"`
-	CreatedAt string `json:"createdAt"`
-	NodeID    string `json:"nodeId"`
+	TargetID   string `json:"targetId"`
+	Title      string `json:"title"`
+	CreatedAt  string `json:"createdAt"`
+	NodeID     string `json:"nodeId"`
+	NodePath   string `json:"nodePath,omitempty"`
 }
 
 // Suggestion represents a suggested worklog entry derived from today's activity.