feat(coverage): 覆盖图节点用 lucide 图标 + 精简 label + 抽屉展示关联意图/事实

- 节点图标 emoji → 平台一致的 lucide 图标(白色 SVG data URI，iconSrc)
- 图内 label：服务显示 端口·标题·状态码(不再完整 URL)，端点只显示 path
- 点节点抽屉新增「关联意图/关联事实/关联发现」：按 exploration_anchors
  反查本任务锚定该资产的节点
  - db AssetRefs(assetID)；server GET /api/tasks/{id}/asset-refs?asset_id=X
  - types/api taskAssetRefs；抽屉按 node.asset_id 拉取渲染

Co-Authored-By: Claude Opus 4.8 <[email protected]>

server/server.go

@@ -484,6 +484,7 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("GET /api/tasks/{id}", s.getTask)
 	mux.HandleFunc("GET /api/tasks/{id}/coverage", s.taskCoverage)
 	mux.HandleFunc("GET /api/tasks/{id}/coverage-graph", s.taskCoverageGraph)
+	mux.HandleFunc("GET /api/tasks/{id}/asset-refs", s.taskAssetRefs)
 	mux.HandleFunc("GET /api/tasks/{id}/scope", s.taskScopeList)
 	mux.HandleFunc("POST /api/tasks/{id}/control", s.control)
 	mux.HandleFunc("POST /api/active", s.setActive)
@@ -1130,6 +1131,40 @@ func (s *Server) taskCoverageGraph(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, 200, g)
 }
 
+// taskAssetRefs returns the intents / facts / findings in this task anchored to a
+// given asset id — powers the coverage-graph node drawer's「关联意图 / 关联事实」。
+func (s *Server) taskAssetRefs(w http.ResponseWriter, r *http.Request) {
+	t, ok := s.m.Task(r.PathValue("id"))
+	if !ok {
+		writeErr(w, 404, "task not found")
+		return
+	}
+	assetID, _ := strconv.ParseInt(r.URL.Query().Get("asset_id"), 10, 64)
+	if assetID <= 0 {
+		writeErr(w, 400, "需要 asset_id")
+		return
+	}
+	refs, err := t.Store.AssetRefs(assetID)
+	if err != nil {
+		writeErr(w, 500, err.Error())
+		return
+	}
+	intents := []db.AssetRef{}
+	facts := []db.AssetRef{}
+	findings := []db.AssetRef{}
+	for _, ref := range refs {
+		switch ref.Kind {
+		case "intent":
+			intents = append(intents, ref)
+		case "fact":
+			facts = append(facts, ref)
+		case "finding":
+			findings = append(findings, ref)
+		}
+	}
+	writeJSON(w, 200, map[string]any{"intents": intents, "facts": facts, "findings": findings})
+}
+
 // taskScopeList returns a task's scope rows (coverage denominator sources).
 func (s *Server) taskScopeList(w http.ResponseWriter, r *http.Request) {
 	t, ok := s.m.Task(r.PathValue("id"))