perf: 筛选统计去掉 JSON 兜底，并补上 orders 覆盖索引

去掉 work_orders 堆访问后，JOIN 会把 orders 整表扫进 Hash Right Join。
领取页在快照新鲜时不再打上游；快手出网统一 10 秒超时。倒计时改为自适应间隔。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/frontend/tests/deadline-countdown.test.ts

@@ -0,0 +1,35 @@
+import assert from 'node:assert/strict'
+import test from 'node:test'
+
+import {
+  DEADLINE_FAST_TICK_MS,
+  DEADLINE_SLOW_TICK_MS,
+  resolveDeadlineCountdown,
+} from '../src/utils/deadline-countdown.ts'
+
+const now = Date.parse('2026-10-01T06:00:00.000Z')
+
+test('deadline under one minute ticks every second and keeps the seconds label', () => {
+  const view = resolveDeadlineCountdown('2026-10-01T06:00:45.000Z', now)
+  assert.equal(view.tickMs, DEADLINE_FAST_TICK_MS)
+  assert.equal(view.label, '剩余 45 秒')
+  assert.equal(view.color, 'orange')
+})
+
+test('deadline over one minute ticks every 30 seconds and hides seconds', () => {
+  const near = resolveDeadlineCountdown('2026-10-01T06:02:20.000Z', now)
+  assert.equal(near.tickMs, DEADLINE_SLOW_TICK_MS)
+  assert.equal(near.label, '剩余 2 分')
+  assert.equal(near.color, 'orange')
+
+  const far = resolveDeadlineCountdown('2026-10-01T06:12:20.000Z', now)
+  assert.equal(far.label, '剩余 12 分')
+  assert.equal(far.color, 'blue')
+})
+
+test('expired deadline stops the one-second timer', () => {
+  const view = resolveDeadlineCountdown('2026-10-01T05:59:00.000Z', now)
+  assert.equal(view.label, '已超时')
+  assert.equal(view.color, 'red')
+  assert.equal(view.tickMs, DEADLINE_SLOW_TICK_MS)
+})