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/pages/service-program/service-program.wxml

@@ -1 +1 @@
-<view class="service-page"><view class="hero"><text class="eyebrow">专项公益服务</text><text class="hero-title">让需要帮助的人被认真看见</text><text class="hero-desc">针对特定群体提供阶段性公益支持，项目条件与服务边界公开透明。</text></view><view class="content"><view class="block"><text class="block-title">青年人才公益交友支持</text><view class="card"><text class="feature-title">服务内容</text><text class="feature-desc">主题活动、资料指导、公益红娘转介与关系成长课堂。</text><text class="feature-title" style="margin-top:24rpx">申请条件</text><text class="feature-desc">以项目当期公布的年龄、工作或居住条件为准，不承诺匹配结果。</text><view><text class="tag">公益免费</text><text class="tag">自愿申请</text><text class="tag">隐私保护</text></view></view></view><view class="notice">项目主办或协作关系不会自动获得用户资料访问权限。</view></view><view class="fixed-action"><view class="primary-btn" bindtap="apply">了解申请方式</view></view></view>
+<view class="service-page"><view class="hero"><text class="eyebrow">专项公益服务</text><text class="hero-title">让需要帮助的人被认真看见</text><text class="hero-desc">针对特定群体提供阶段性公益支持，项目条件与服务边界公开透明。</text></view><view class="content"><view wx:if="{{loading}}" class="card empty-panel"><view class="empty-symbol">…</view><text class="empty-title">正在加载</text></view><view wx:elif="{{error}}" class="card empty-panel"><view class="empty-symbol">!</view><text class="empty-title">{{error}}</text></view><view wx:elif="{{programs.length}}" class="block"><view wx:for="{{programs}}" wx:key="id" class="card"><view style="display:flex;justify-content:space-between"><text class="feature-title">{{item.name}}</text><text class="tag">{{item.status}}</text></view><text class="feature-desc" style="margin-top:16rpx">{{item.description}}</text><view><text class="tag">公益免费</text><text class="tag">自愿申请</text><text class="tag">隐私保护</text></view><view wx:if="{{item.applicable}}" class="primary-btn" style="margin-top:24rpx" data-id="{{item.id}}" bindtap="apply">申请加入</view></view></view><view wx:else class="card empty-panel"><view class="empty-symbol">项</view><text class="empty-title">暂无可申请的专项服务</text><text class="meta">新项目上线后会在这里公布。</text></view></view><view class="notice">项目主办或协作关系不会自动获得用户资料访问权限。</view></view></view>