feat(web): 任务详情页新增探索链路播报板

按创建时间分页平铺展示探索节点,作为探索链路图的时间轴视图,
复用同一份 exploration_nodes 数据,不影响链路图。

- 后端 NodesPage/NodesByIDs/EdgesTouching:分页下推 SQL,
  支持 kind/state 过滤、payload/origin 搜索、正倒序,
  并补出当页节点的相邻边与对端节点
- 新增 GET /api/exploration/nodes(仅本任务节点,不含继承)
- 播报板:时间轴分行、按天分组、类型快筛、搜索防抖、
  自动刷新、直播位未读提示、展开看上下游与 payload
- 补 mock,NEXT_PUBLIC_MOCK=1 下可无后端预览

server/server.go

@@ -858,6 +858,7 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("DELETE /api/exploration/findings/{id}", s.deleteFinding)
 	mux.HandleFunc("GET /api/exploration/intents", s.intents)
 	mux.HandleFunc("GET /api/exploration/graph", s.explorationGraph)
+	mux.HandleFunc("GET /api/exploration/nodes", s.explorationNodes)
 	mux.HandleFunc("GET /api/exploration/activity", s.activity)
 	mux.HandleFunc("GET /api/exploration/activity/history", s.activityHistory)
 	mux.HandleFunc("GET /api/exploration/main-sessions", s.mainSessions)
@@ -2576,6 +2577,90 @@ func (s *Server) explorationGraph(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, 200, map[string]any{"nodes": taskNodeDTOs(nodes), "edges": edgeDTOs(edges)})
 }
 
+// explorationNodes serves the 播报板: this task's own exploration nodes as a
+// paged time series (newest first unless ?order=asc), filterable by kind/state
+// and a payload substring. Inherited nodes are deliberately out of scope — the
+// board reports what this task is doing right now, and paging across the source
+// tasks' stores would make the cursor meaningless.
+// Response also carries the edges touching the page plus the neighbour nodes
+// they point at, so each row can state where it came from and what it produced.
+func (s *Server) explorationNodes(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query()
+	page := atoiDefault(q.Get("page"), 1)
+	size := atoiDefault(q.Get("size"), 20)
+	t := s.m.ResolveTask(q.Get("task"))
+	if t == nil {
+		writeJSON(w, 200, map[string]any{
+			"items": []any{}, "total": 0, "page": page, "size": size,
+			"edges": []any{}, "refs": map[string]any{},
+		})
+		return
+	}
+	filter := db.NodeFilter{
+		Kinds:  csvValues(q.Get("kind")),
+		States: csvValues(q.Get("state")),
+		Query:  q.Get("q"),
+		Asc:    q.Get("order") == "asc",
+	}
+	nodes, total, err := t.Store.NodesPage(filter, page, size)
+	if err != nil {
+		writeErr(w, 500, err.Error())
+		return
+	}
+	ids := make([]int64, 0, len(nodes))
+	onPage := make(map[int64]bool, len(nodes))
+	for _, n := range nodes {
+		ids = append(ids, n.ID)
+		onPage[n.ID] = true
+	}
+	edges, err := t.Store.EdgesTouching(ids)
+	if err != nil {
+		writeErr(w, 500, err.Error())
+		return
+	}
+	neighbourSet := map[int64]bool{}
+	for _, e := range edges {
+		if !onPage[e.From] {
+			neighbourSet[e.From] = true
+		}
+		if !onPage[e.To] {
+			neighbourSet[e.To] = true
+		}
+	}
+	neighbourIDs := make([]int64, 0, len(neighbourSet))
+	for id := range neighbourSet {
+		neighbourIDs = append(neighbourIDs, id)
+	}
+	neighbours, err := t.Store.NodesByIDs(neighbourIDs)
+	if err != nil {
+		writeErr(w, 500, err.Error())
+		return
+	}
+	refs := make(map[string]TaskNodeDTO, len(neighbours))
+	for _, n := range neighbours {
+		refs[i64s(n.ID)] = taskNodeDTO(n)
+	}
+	writeJSON(w, 200, map[string]any{
+		"items": taskNodeDTOs(nodes),
+		"total": total,
+		"page":  page,
+		"size":  size,
+		"edges": edgeDTOs(edges),
+		"refs":  refs,
+	})
+}
+
+// csvValues splits a comma-separated query parameter, dropping empty entries.
+func csvValues(s string) []string {
+	out := []string{}
+	for _, part := range strings.Split(s, ",") {
+		if v := strings.TrimSpace(part); v != "" {
+			out = append(out, v)
+		}
+	}
+	return out
+}
+
 // activity returns the worker execution step log (incremental via ?since=seq).
 func (s *Server) activity(w http.ResponseWriter, r *http.Request) {
 	t := s.m.ResolveTask(r.URL.Query().Get("task"))