perf(worker): 持久化准入快照提升队列吞吐

原因：线上 P24 验收显示 Worker 在每轮准入前逐条恢复媒体、重算候选和查询 attempts，跨地域查询导致 48 个执行槽长期只能使用约 8 至 16 个。\n\n影响：任务首次排队时保存鉴权后的 admission scope 快照，Worker 单次批量读取并只刷新动态总容量；显式重新选路保留完整慢路径。验收模拟器改到非数据库专用 Worker 节点，运行期 85% 作为立即中止硬门禁，80% 继续作为容量认证目标。\n\n验证：Go 全量测试、go vet、govulncheck、真实 PostgreSQL 迁移与跨 Store 集成测试、ShellCheck、发布及验收脚本、OpenAPI、前端 lint/test/build、pnpm audit high、Compose 与 Kubernetes 渲染均通过。

tests/release/production-acceptance-script-test.sh

@@ -108,10 +108,12 @@ grep -Fq '# target_host root@hongkong-worker-2.invalid' <<<"$metrics"
 [[ $(metric_max test_metric <<<"$metrics") == 1 ]]
 [[ $(metric_sum test_metric <<<"$metrics") == 2 ]]
 
-passing_pressure_row='2026-08-01T00:00:00Z,0,0,899,149,200,79,1535,0,32,32,0,0,0,0,2,48,0,8,8,0,0,0,16,16,0,0,1535,100'
+passing_pressure_row='2026-08-01T00:00:00Z,0,0,899,149,200,84,1535,0,32,32,0,0,0,0,2,48,0,8,8,0,0,0,16,16,0,0,1535,100'
 pressure_row_passes_live_gates "$passing_pressure_row"
 [[ $(pressure_row_live_gate_reason '2026-08-01T00:00:00Z,0,0,900,149,200,79,1535,0,32,32,0,0,0,0,2,48,0,8,8,0,0,0,16,16,0,0,1535,100') == \
   'oldest_wait_seconds=900 limit=900' ]]
+[[ $(pressure_row_live_gate_reason '2026-08-01T00:00:00Z,0,0,899,149,200,85,1535,0,32,32,0,0,0,0,2,48,0,8,8,0,0,0,16,16,0,0,1535,100') == \
+  'node_memory_percent=85 hard_limit=85' ]]
 
 for failed_pressure_row in \
   '2026-08-01T00:00:00Z,0,0,901,149,200,79,1535,0,32,32,0,0,0,0,2,48,0,8,8,0,0,0,16,16,0,0,1535,100' \