feat(findings): 发现页新增「按资产」视图

左侧资产树 + 右侧该子树下的发现,与另外两个视图共用同一张表和同一批筛选。

后端
- db/finding_assets.go:按当前筛选构建资产树。只收有发现的资产,祖先链逐层
  补齐(endpoint→service→subdomain/ip→root_domain),父子优先级与
  BuildCoverageGraph 同源;计数沿祖先链去重累加,一条发现挂多个资产不会让
  父节点重复计数
- FindingFilter 加 AssetScope:选中节点=选中整棵子树,解析成资产 id 集合后
  下推 SQL,列表 / 分组 / 导出三个入口共用,导出「当前筛选」自动带上
- 「未关联资产」同时收 asset_ids 为空与指向已删资产的发现,与树上桶的口径
  一致(只判空数组会让桶上的数字大于点开后的条数)
- findingFilterFromQuery 统一四处的筛选解析;新增 GIN 索引
  idx_findings_asset_ids,按资产反查发现不再全表扫

前端
- 树默认展开一层,支持过滤(匹配项自动展开)、面包屑下钻、手动刷新
- 每层只显示相对上一层的增量:子域名去根域名后缀、服务显示 `https :443`、
  接口只留路径。完整值在 title 与面包屑,搜索仍按完整值匹配
- 不轮询:进入视图 / 改筛选 / 页内改动发现 / 点刷新时才查
- 节点超上限时整层丢弃接口/服务并提示,计数已在上层不会丢

server/findings_groups.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"net/url"
 	"strings"
 	"unicode/utf8"
 
@@ -24,6 +25,32 @@ func findingPaginationParam(raw string, fallback, upperBound int) int {
 	return value
 }
 
+// findingFilterFromQuery builds the shared findings filter from a request's
+// query string. 列表 / 分组 / 资产树 / 导出走同一份解析,新增筛选项只改这里。
+func findingFilterFromQuery(q url.Values) db.FindingFilter {
+	return db.FindingFilter{
+		Severity:  normFilter(q.Get("severity")),
+		Status:    normFilter(q.Get("status")),
+		VulnClass: normFilter(q.Get("vulnclass")),
+		// task_id(独立于会切到「按任务节点」分支的 task 参数):全局表按任务筛选。
+		TaskID:     normFilter(q.Get("task_id")),
+		Query:      q.Get("q"),
+		Sort:       q.Get("sort"),
+		AssetScope: strings.TrimSpace(q.Get("asset_scope")),
+	}
+}
+
+// findingAssetTree serves the「按资产」view's left-hand tree: every asset that
+// carries at least one matching finding, plus the ancestors needed to place it.
+func (s *Server) findingAssetTree(w http.ResponseWriter, r *http.Request) {
+	tree, err := s.m.pg.BuildFindingAssetTree(findingFilterFromQuery(r.URL.Query()))
+	if err != nil {
+		writeErr(w, 500, err.Error())
+		return
+	}
+	writeJSON(w, 200, tree)
+}
+
 // findingGroups serves the task-group page used by the global findings view.
 // Findings inside a group continue to use the existing flat findings endpoint,
 // preserving dashboard/export clients and giving every expanded group its own
@@ -32,15 +59,7 @@ func (s *Server) findingGroups(w http.ResponseWriter, r *http.Request) {
 	q := r.URL.Query()
 	page := findingPaginationParam(q.Get("page"), 1, 0)
 	limit := findingPaginationParam(q.Get("limit"), 10, 100)
-	filter := db.FindingFilter{
-		Severity:  normFilter(q.Get("severity")),
-		Status:    normFilter(q.Get("status")),
-		VulnClass: normFilter(q.Get("vulnclass")),
-		TaskID:    normFilter(q.Get("task_id")),
-		Query:     q.Get("q"),
-		Sort:      q.Get("sort"),
-	}
-	groups, total, findingTotal, err := s.m.pg.ListFindingGroups(filter, page, limit)
+	groups, total, findingTotal, err := s.m.pg.ListFindingGroups(findingFilterFromQuery(q), page, limit)
 	if err != nil {
 		writeErr(w, 500, err.Error())
 		return

server/server.go

@@ -775,6 +775,7 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("GET /api/exploration/frontier", s.frontier)
 	mux.HandleFunc("GET /api/exploration/findings", s.findings)
 	mux.HandleFunc("GET /api/exploration/findings/groups", s.findingGroups)
+	mux.HandleFunc("GET /api/exploration/findings/asset-tree", s.findingAssetTree)
 	mux.HandleFunc("GET /api/exploration/findings/stats", s.findingStats)
 	mux.HandleFunc("GET /api/exploration/findings/export", s.findingsExport)
 	mux.HandleFunc("GET /api/exploration/findings/{id}", s.getFinding)
@@ -1887,16 +1888,7 @@ func (s *Server) findings(w http.ResponseWriter, r *http.Request) {
 		}
 		page := findingPaginationParam(q.Get("page"), 1, 0)
 		limit := findingPaginationParam(q.Get("limit"), 20, 200)
-		filter := db.FindingFilter{
-			Severity:  normFilter(q.Get("severity")),
-			Status:    normFilter(q.Get("status")),
-			VulnClass: normFilter(q.Get("vulnclass")),
-			// task_id(独立于会切到「按任务节点」分支的 task 参数):全局表按任务筛选。
-			TaskID: normFilter(q.Get("task_id")),
-			Query:  q.Get("q"),
-			Sort:   q.Get("sort"),
-		}
-		fs, total, err := s.m.pg.ListFindingsPage(filter, page, limit)
+		fs, total, err := s.m.pg.ListFindingsPage(findingFilterFromQuery(q), page, limit)
 		if err != nil {
 			writeErr(w, 500, err.Error())
 			return
@@ -2092,14 +2084,7 @@ func (s *Server) findingsExport(w http.ResponseWriter, r *http.Request) {
 	case "all":
 		// 空 filter = 不加任何条件。
 	case "filtered", "":
-		filter = db.FindingFilter{
-			Severity:  normFilter(q.Get("severity")),
-			Status:    normFilter(q.Get("status")),
-			VulnClass: normFilter(q.Get("vulnclass")),
-			TaskID:    normFilter(q.Get("task_id")),
-			Query:     q.Get("q"),
-			Sort:      q.Get("sort"),
-		}
+		filter = findingFilterFromQuery(q)
 	default:
 		writeErr(w, 400, "bad scope: "+scope)
 		return