feat(lineage): Phase 2 — materialized view + throttled refresh + UI staleness

dict-relationships-v2 epic, Phase 2. Precomputed reverse FK index +
throttled refresh + feature flag + UI staleness badge. Migration катится
всегда; query path активируется через ordinis.lineage.mv.enabled=true.

Backend:
- Liquibase 0016: CREATE MATERIALIZED VIEW record_dependents_index +
  UNIQUE INDEX(source_record_id, source_field) (REQUIRED для REFRESH
  CONCURRENTLY) + composite indices для record-level и schema-level lookup.
  Plus lineage_mv_meta table — single-row tracking (last_refreshed_at,
  duration_ms, row_count, status, error).
- DependentsQueryMv (interface impl, @Primary + @ConditionalOnProperty)
  — один SQL query через MV вместо N JSONB lookups (по одному per
  source dict).
- MaterializedViewRefreshService:
  * @Scheduled refresh каждые ordinis.lineage.mv.refresh-interval-sec
    (default 60). Storm prevention: AtomicReference guard для in-flight,
    cooldown через ordinis.lineage.mv.min-interval-sec (default 30).
  * REFRESH CONCURRENTLY с fallback на plain REFRESH когда MV пустой
    (initial state). Не блокирует concurrent reads.
  * MvGateway interface (extracted из-за JDK 25 + Mockito incompat для
    concrete JdbcTemplate). Production: JdbcMvGateway (nested static).
- LineageIndexService теперь возвращает LineageMeta в RecordDependentsPage
  — mvEnabled, lastRefreshedAt, lastStatus, lastDurationMs. Optional<MV>
  inject — works без MV (mvEnabled=false, всё null).

Tests:
- MaterializedViewRefreshServiceTest (9 tests):
  * scheduledRefresh first time → REFRESH CONCURRENTLY
  * skip when within cooldown
  * refreshNow throws RefreshThrottledException when throttled
  * refresh succeeds после cooldown
  * fallback на plain REFRESH когда CONCURRENTLY fails
  * STORM PREVENTION (R2): 100 concurrent refresh attempts → ровно 1
    actual refresh (via cooldown + in-flight guard)
  * lastRefresh returns meta correctly
  * updates lineage_mv_meta after refresh (status=ok)
  * updates with error если оба refresh'а fail (status=error)

Admin UI:
- RecordDependentsPage type расширен LineageMeta { mvEnabled,
  lastRefreshedAt, lastStatus, lastDurationMs }.
- RecordDependentsPanel показывает staleness badge "обновлено N мин
  назад" если MV active + last refresh > 2 min ago. Tooltip объясняет
  что closed-between-refreshes records отфильтрованы query-side.
- i18n RU/EN: lineage.refs.{stale, staleHint}.

Verify:
- mvn -pl ordinis-rest-api -am test: 98/98 PASS (+9 new MV tests).
- mvn verify -pl '!ordinis-app': все модули SUCCESS (9.3s).
- pnpm tsc --noEmit: clean.
- pnpm test (vitest): 89/89 PASS.

Deploy strategy:
- Migration катится автоматом (initial REFRESH < 5 min на 5k records).
- Query path остаётся JSONB direct (Phase 1) до явного flip flag'а
  ordinis.lineage.mv.enabled=true. Это позволит верифицировать MV
  корректность на staging без риска для prod.
- После flip: refresh каждые 60 sec, stale window <= 2 min обычно.

ordinis-admin-ui/src/api/client.ts

@@ -276,6 +276,16 @@ export type PerSourceSummary = {
   count: number
 }
 
+export type LineageMeta = {
+  /** True если backend использует materialized view; false — JSONB direct (fresh). */
+  mvEnabled: boolean
+  /** ISO timestamp последнего успешного MV refresh; null если MV выключена / never. */
+  lastRefreshedAt: string | null
+  /** "ok" | "error" | "never" — null если mvEnabled=false. */
+  lastStatus: string | null
+  lastDurationMs: number | null
+}
+
 export type RecordDependentsPage = {
   targetDict: string
   targetBusinessKey: string
@@ -284,6 +294,8 @@ export type RecordDependentsPage = {
   total: number
   page: number
   size: number
+  /** Phase 2 dict-relationships-v2: backing data source metadata + staleness. */
+  lineageMeta?: LineageMeta | null
 }
 
 export type WebhookTestPingResult = {