fix(ops-backend/service-station): close Phase 19 KEEP-VERIFY — 25 defects (unreachable announcements + station write privilege escalation; banner 500 + soft-delete leak; content publish dead-end; program approval dead-end/draft leak/zero counts/missing withdraw; zero-coverage test schema) ; add V042 announcement chain + 34 guard tests; full regression 602 green

Backend
- Service Station: expose the 「临时公告」 chain end-to-end (V042 table/service existed
  but had ZERO endpoints -> both admin and miniapp could never reach it): 5 operator
  endpoints (list/create/update/publish/archive) + 1 user-facing read endpoint.
- Fix privilege escalation: create/update were guarded only by the class-level
  service_location.view, making V015's service_location.manage a never-used dead
  permission -> read-only roles could edit stations. Permissions moved to method level.
- Add ServiceLocationOperatorController to OperatorEndpointPermissionCoverageTest
  (it was NOT scanned, which is why the escalation stayed invisible).
- Add create/update validation (address NOT NULL + status CHECK only blew up on PG).
- Banner: validation failures threw bare RuntimeException -> 500; now VALIDATION_ERROR
  -> 400. Add deleted_at IS NULL to both home queries (soft-deleted banners stayed live).
- Content: operator list/detail split (admin «publish» was a dead end because it reused
  the published-only public API); category deactivate/reactivate; article body on edit.
- Service Program: operator member list now includes pending (approval reachable);
  active-only public visibility (draft leak); memberCount/pendingCount aggregation;
  withdraw/removeMember; reuse row on re-apply (UNIQUE(program_id,user_id) crash).
- MeController: add the missing GET /me/service-history route.

Schema / guards
- schema-h2.sql: add service_location_announcements (+ chk_announcement_status) and
  content_categories (+ uk_content_category_code, chk_category_status); move both into
  REQUIRED_IN_TEST_SCHEMA. MigrationValidationTest baseline 41 -> 42.
- V11PermissionMatrixContractTest now scans ALL migrations instead of hardcoding V015+V029.
- New: ServiceLocationAnnouncementPhase19IntegrationTest (24),
  ServiceLocationControllerPermissionContractTest (5),
  ServiceLocationAnnouncementConstraintParityTest (5, prod DDL <-> test schema <->
  backend whitelist <-> admin labels).

Frontend
- admin-web: ServiceStationView gains announcement management (statuses, create/edit,
  publish/archive with confirm, expiry); write buttons gated by service_location.manage.
- miniapp: U50 renders the 临时公告 block via new serviceStationService; page no longer
  talks to utils/api directly; announcement failure degrades to [] instead of erroring.
- ui-tests: U37 four-group + U50 announcement contracts; /home assertion retargeted to
  the service layer.

Verification
- Negative verification: 3 injected defects (drop soft-delete filter / drop test-schema
  CHECK / downgrade write endpoint to view) -> 4 named tests fail precisely, no
  collateral failures; restored, NEG-VAL residue = 0.
- Backend full regression: 602 tests, 0 failures, 0 errors, 3 skipped (baseline 420).
- admin-web: vue-tsc --noEmit EXIT=0, vite build EXIT=0. Miniapp: tsc --noEmit EXIT=0.
- ui-tests 14/14 PASS.

miniapp/services/serviceStationService.js

@@ -0,0 +1,52 @@
+/**
+ * 善缘服务站（U50）服务层。
+ *
+ * Phase 19：U50 的内容清单包含「临时公告 / 开放时间 / 服务项目 / 预约到站」，
+ * 但公告此前**全仓没有任何存储与接口**，页面也无落点。本轮补齐后端
+ * （V042 + 运营端五个端点 + 用户端只读端点）后由此接入。
+ *
+ * 分层：按 services/index.js 的约定，页面不直接 require utils/api，
+ * 统一从本模块取数据（本站点主体信息来自首页聚合，公告来自服务站公告端点）。
+ *
+ * 契约：
+ *   GET /home                                  → 当前服务站主体信息
+ *   GET /service-locations/{id}/announcements  → 仅 status=published 且未过期
+ *     草稿/归档/过期由服务端过滤，前端不得再做"猜测式"过滤，
+ *     否则等于把未定稿内容拿到客户端。
+ */
+const api = require('../utils/api');
+
+/**
+ * 当前展示的服务站（首页聚合给出的唯一站点）。
+ * @returns {Promise<object|null>}
+ */
+async function getStation() {
+  const home = await api.get('/home');
+  return (home && home.serviceLocation) || null;
+}
+
+/**
+ * 某服务站的可见临时公告。
+ *
+ * 公告属**增强信息**：请求失败时返回空数组而不抛出，
+ * 避免"公告接口挂了导致整个服务站详情页变成错误页"。
+ * @param {string} locationId
+ * @returns {Promise<Array<{id: string, title: string, content?: string}>>}
+ */
+async function getVisibleAnnouncements(locationId) {
+  if (!locationId) {
+    return [];
+  }
+  try {
+    const list = await api.get(`/service-locations/${encodeURIComponent(locationId)}/announcements`);
+    return Array.isArray(list) ? list : [];
+  } catch (err) {
+    console.warn('加载服务站公告失败', err);
+    return [];
+  }
+}
+
+module.exports = {
+  getStation,
+  getVisibleAnnouncements,
+};