feat: 增加 Agent 流量绑定开关并补齐证据交接

db/exploration.go

@@ -31,6 +31,9 @@ func utf8Clean(s string) string {
 
 // Node is a typed reasoning node (= old task_nodes). kind ∈ goal|intent|finding|hint.
 type Node struct {
+	FindingID     int64           `json:"finding_id,omitempty"` // populated by finding-aware reads; never inferred from ID
+	FindingNodeID int64           `json:"finding_node_id,omitempty"`
+	TrafficCount  int             `json:"traffic_count,omitempty"`
 	ID            int64           `json:"id"`
 	Kind          string          `json:"kind"`
 	Payload       json.RawMessage `json:"payload"`