fix(pool): 配额倒计时归零后进度条与列表恢复显示 100%

- 后端读取层 provider_key_status_snapshot_payload 复用调度侧同一判定
  provider_pool_reset_deadline_elapsed，对已到期的 Codex 配额窗口归一化为
  used_ratio=0 / remaining_ratio=1，并清除窗口级耗尽标记；跳过
  window_minutes=0 与无用量观测的窗口
- 前端展示层在倒计时归零（isExpired）时兜底显示 100%，并隐藏重置前的旧用量
  文本，保证归零瞬间即时恢复，与后端读取口径、调度口径一致
- 补充后端 2 个单测（到期归一化、遗留耗尽状态清理）与前端 1 个回归用例
  （负向验证可复现旧行为）

验证：aether-provider-pool 71/71；aether-gateway lib 回归通过（仅 3 个依赖
PostgreSQL 服务端的用例因本机环境缺失失败，与本改动无关）；前端 222 文件 /
1718 用例全部通过；clippy -D warnings、cargo fmt、vue-tsc、eslint 均通过。

frontend/src/views/admin/__tests__/PoolManagement.codex-cycle-stats.spec.ts

@@ -35,6 +35,10 @@ const routeMocks = vi.hoisted(() => ({
   }),
 }))
 
+const countdownMocks = vi.hoisted(() => ({
+  isExpired: false,
+}))
+
 const proxyStoreMocks = vi.hoisted(() => ({
   ensureLoaded: vi.fn(),
 }))
@@ -106,7 +110,7 @@ vi.mock('@/composables/useCountdownTimer', async () => {
       start: vi.fn(),
     }),
     getCodexResetCountdown: () => ({
-      isExpired: false,
+      isExpired: countdownMocks.isExpired,
       text: '1h',
     }),
   }
@@ -604,6 +608,7 @@ beforeEach(() => {
   window.sessionStorage.clear()
   routeMocks.patchQuery.mockClear()
   proxyStoreMocks.ensureLoaded.mockClear()
+  countdownMocks.isExpired = false
 
   endpointMocks.getPoolOverview.mockReset()
   endpointMocks.getPoolSchedulingPresets.mockReset()
@@ -736,6 +741,44 @@ describe('PoolManagement Codex cycle stats mode', () => {
     expect(root.textContent).toContain('生图')
   })
 
+  it('shows expired Codex quota windows as fully restored', async () => {
+    countdownMocks.isExpired = true
+    const expiredKey = createPoolKey('codex', {
+      status_snapshot: {
+        oauth: { code: 'valid' },
+        account: { code: 'ok', blocked: false },
+        quota: {
+          code: 'ok',
+          exhausted: false,
+          provider_type: 'codex',
+          windows: [
+            {
+              code: '5h',
+              label: '5H',
+              scope: 'account',
+              remaining_ratio: 0.12,
+              reset_at: 1_700_000_000,
+              window_minutes: 300,
+            },
+          ],
+        },
+      },
+    })
+    endpointMocks.getPoolOverview.mockResolvedValue({ items: [createOverview('codex')] })
+    endpointMocks.listPoolKeys.mockResolvedValue(createKeyPage(expiredKey))
+    endpointMocks.getProvider.mockResolvedValue(createProvider('codex'))
+
+    const root = mountPoolManagement()
+    await settle()
+
+    // 倒计时归零后进度条与文本按“已重置”显示 100%，不再显示旧百分比。
+    expect(root.querySelector('[data-testid="pool-quota-meter-text"]')?.textContent?.trim()).toBe('100.0%')
+    const track = root.querySelector('[data-testid="pool-quota-progress-track"]')
+    const bar = track?.firstElementChild as HTMLElement | null
+    expect(bar?.style.width).toBe('100%')
+    expect(root.querySelector('[data-testid="pool-quota-reset-text"]')).toBeNull()
+  })
+
   it('labels Codex quota by the actual refresh window duration', async () => {
     const monthlyCodexKey = createPoolKey('codex', {
       status_snapshot: {