feat(selection): show stock industry and concept boards in detail panel

Add point-in-time stock membership lookup to the sector radar module
(GET /sector-radar/stocks/{ts_code}/membership) reading the existing
dc_index/dc_member snapshots, and surface industries plus concept chips
in the selection signal detail panel with graceful no-data hiding.

zhixing-web/src/features/sector-radar/api/sector-radar.api.test.ts

@@ -4,7 +4,11 @@ const requestJson = vi.hoisted(() => vi.fn())
 
 vi.mock("@/shared/api/request-json", () => ({ requestJson }))
 
-import { getSectorRadarDates, getSectorRadarRankings } from "./sector-radar.api"
+import {
+  getSectorRadarDates,
+  getSectorRadarRankings,
+  getStockSectorMembership,
+} from "./sector-radar.api"
 
 const publication = {
   publication_id: "publication-1",
@@ -180,3 +184,59 @@ describe("sector radar API adapters", () => {
     ).rejects.toThrow("rankings.rows[0].rank_percentile must be greater than 0")
   })
 })
+
+describe("stock sector membership adapter", () => {
+  const membershipPayload = {
+    status: "success",
+    ts_code: "000001.SZ",
+    requested_trade_date: "2026-08-28",
+    trade_date: "2026-08-28",
+    industries: [{ code: "BK0901.DC", name: "银行" }],
+    concepts: [
+      { code: "BK0001.DC", name: "机器人" },
+      { code: "BK0002.DC", name: "人工智能" },
+    ],
+    concept_total: 2,
+    concept_limit: 20,
+  }
+
+  it("requests the snake-case endpoint and validates the payload", async () => {
+    requestJson.mockResolvedValue(membershipPayload)
+
+    const result = await getStockSectorMembership("000001.SZ", "2026-08-28")
+
+    expect(requestJson).toHaveBeenCalledWith(
+      "/api/v1/sector-radar/stocks/000001.SZ/membership?trade_date=2026-08-28",
+      { signal: undefined },
+    )
+    expect(result).toEqual(membershipPayload)
+  })
+
+  it("keeps the no_data status with a null snapshot date", async () => {
+    requestJson.mockResolvedValue({
+      ...membershipPayload,
+      status: "no_data",
+      trade_date: null,
+      industries: [],
+      concepts: [],
+      concept_total: 0,
+    })
+
+    const result = await getStockSectorMembership("000001.SZ", "2026-08-28")
+
+    expect(result.status).toBe("no_data")
+    expect(result.trade_date).toBeNull()
+    expect(result.industries).toEqual([])
+  })
+
+  it("rejects a membership response with invalid sector references", async () => {
+    requestJson.mockResolvedValue({
+      ...membershipPayload,
+      industries: [{ code: "BK0901.DC", name: " " }],
+    })
+
+    await expect(
+      getStockSectorMembership("000001.SZ", "2026-08-28"),
+    ).rejects.toThrow("membership.industries[0].name must be a non-empty string")
+  })
+})