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-appointment/service-appointment.wxml

@@ -1 +1 @@
-<view class="service-page"><view class="hero"><text class="eyebrow">U51 服务预约</text><text class="hero-title">预约到站服务</text><text class="hero-desc">选择合适的时间和服务项目，提交后等待工作人员确认。</text></view><view class="content"><view class="card"><view class="field"><text class="label">服务项目</text><picker range="{{services}}" bindchange="chooseService"><view class="select-box">{{service}}<text class="arrow" style="margin-left:auto">›</text></view></picker></view><view class="field"><text class="label">预约日期</text><picker mode="date" bindchange="chooseDate"><view class="select-box">{{date || '请选择日期'}}</view></picker></view><view class="field"><text class="label">希望沟通的事项（选填）</text><textarea class="textarea" placeholder="请简要说明，避免填写身份证号等敏感信息" maxlength="200"/></view><view class="notice">提交预约不代表已确认。工作人员确认后，预约状态会更新为“已确认”。</view></view></view><view class="fixed-action"><view class="primary-btn" bindtap="submit">提交预约</view></view></view>
+<view class="service-page"><view class="hero"><text class="eyebrow">U51 服务预约</text><text class="hero-title">预约到站服务</text><text class="hero-desc">选择合适的时间和服务项目，提交后等待工作人员确认。</text></view><view class="content"><view class="card"><view class="field" wx:if="{{serviceLocationId}}"><text class="label">服务站点</text><view class="select-box is-readonly">{{serviceLocationName || '已选服务站点'}}</view></view><view class="field"><text class="label">服务项目</text><picker range="{{services}}" bindchange="chooseService"><view class="select-box">{{service}}<text class="arrow" style="margin-left:auto">›</text></view></picker></view><view class="field"><text class="label">预约日期</text><picker mode="date" bindchange="chooseDate"><view class="select-box">{{date || '请选择日期'}}</view></picker></view><view class="field"><text class="label">希望沟通的事项（选填）</text><textarea class="textarea" value="{{note}}" bindinput="onNoteInput" placeholder="请简要说明，避免填写身份证号等敏感信息" maxlength="200"/></view><view class="notice">提交预约不代表已确认。工作人员确认后，预约状态会更新为“已确认”。</view></view></view><view class="fixed-action"><view class="primary-btn {{submitting ? 'is-disabled' : ''}}" bindtap="submit">{{submitting ? '提交中…' : '提交预约'}}</view></view></view>