task-94(店铺中心): 实现店铺凭证明文短时展示

新增 shop-credential-reveal.ts：复用 secret-mask 会话，店铺密码读取后默认
5 秒短时展示，读取失败/离开即清空，明文不写持久化/日志。

TDD: task-94.test.ts 8 用例先 RED 后 GREEN。

admin-frontend-vue/src/pages/shop/shop-credential-reveal.ts

@@ -0,0 +1,38 @@
+/** 店铺密码短时揭示会话（任务 94）：读取明文后只在内存按短窗口(默认 5 秒)展示，
+ * 读取失败或离开页面即清空；纯逻辑，明文不写持久化/日志。 */
+import {
+  DEFAULT_REVEAL_MS,
+  createSecretRevealState,
+  expireReveal,
+  revealSecret,
+  type SecretRevealState,
+} from './secret-mask.ts'
+
+export const DEFAULT_SHOP_PASSWORD_REVEAL_MS = DEFAULT_REVEAL_MS
+
+/** 空揭示会话（默认/读取失败/离开页面后）。 */
+export function clearShopPasswordReveal(): SecretRevealState {
+  return createSecretRevealState()
+}
+
+/** 开始揭示某店铺密码明文（记录 id + 明文 + 揭示时刻），返回新会话。 */
+export function beginShopPasswordReveal(
+  session: SecretRevealState,
+  shopId: number,
+  plain: string,
+  now: number,
+  expiresAt?: number,
+): SecretRevealState {
+  return revealSecret(session, shopId, plain, now, expiresAt)
+}
+
+/** 到达过期点即清空明文。 */
+export function expireShopPasswordReveal(session: SecretRevealState, now: number): SecretRevealState {
+  return expireReveal(session, now)
+}
+
+/** 当前时刻是否存在有效的短时揭示明文。 */
+export function isShopPasswordRevealActive(session: SecretRevealState, now: number): boolean {
+  const current = expireReveal(session, now)
+  return current.keyId !== null && current.token !== undefined && current.token !== ''
+}

admin-frontend-vue/tests/task-94.test.ts

@@ -0,0 +1,72 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { readSource } from './helpers.ts'
+import {
+  DEFAULT_SHOP_PASSWORD_REVEAL_MS,
+  beginShopPasswordReveal,
+  clearShopPasswordReveal,
+  expireShopPasswordReveal,
+  isShopPasswordRevealActive,
+} from '../src/pages/shop/shop-credential-reveal.ts'
+
+test('test_task_094_credential_reveal_normal_primary_path', () => {
+  // 正常主路径：主动揭示后短时(默认 5 秒)拿到明文，超时自动清空。
+  const session = beginShopPasswordReveal(clearShopPasswordReveal(), 5, 'plain-pw', 1000)
+  assert.equal(isShopPasswordRevealActive(session, 1000), true)
+  assert.equal(session.token, 'plain-pw')
+  const expired = expireShopPasswordReveal(session, 1000 + DEFAULT_SHOP_PASSWORD_REVEAL_MS + 1)
+  assert.equal(expired.token, undefined, '超时明文被清空')
+  assert.equal(isShopPasswordRevealActive(expired, 7000), false)
+})
+
+test('test_task_094_credential_reveal_normal_variant_input', () => {
+  // 正常变体：多个店铺各自揭示互不串扰，切换记录即替换明文。
+  const first = beginShopPasswordReveal(clearShopPasswordReveal(), 1, 'pw1', 0)
+  const second = beginShopPasswordReveal(first, 2, 'pw2', 0)
+  assert.equal(second.keyId, 2)
+  assert.equal(second.token, 'pw2')
+})
+
+test('test_task_094_credential_reveal_repeated_is_idempotent', () => {
+  // 正常重复：同一时刻重复揭示结果稳定。
+  const a = beginShopPasswordReveal(clearShopPasswordReveal(), 3, 'pw', 2000)
+  assert.deepEqual(beginShopPasswordReveal(a, 3, 'pw', 2000), a)
+})
+
+test('test_task_094_credential_reveal_boundary_empty_input', () => {
+  // 边界空值：清空后无活动揭示、无明文残留。
+  const session = clearShopPasswordReveal()
+  assert.equal(session.keyId, null)
+  assert.equal(isShopPasswordRevealActive(session, 0), false)
+})
+
+test('test_task_094_credential_reveal_boundary_single_item', () => {
+  // 边界单元素：单次揭示在窗口内有效，离开(调用清空)立即释放。
+  const session = beginShopPasswordReveal(clearShopPasswordReveal(), 9, 'pw9', 0, 0 + DEFAULT_SHOP_PASSWORD_REVEAL_MS)
+  assert.equal(isShopPasswordRevealActive(session, DEFAULT_SHOP_PASSWORD_REVEAL_MS - 1), true)
+  const gone = clearShopPasswordReveal()
+  assert.equal(isShopPasswordRevealActive(gone, 0), false)
+})
+
+test('test_task_094_credential_reveal_boundary_limit_or_missing_field', () => {
+  // 边界上限：跨记录的揭示不会在离开/失败后残留在其它状态里。
+  const session = beginShopPasswordReveal(clearShopPasswordReveal(), 4, 'x'.repeat(600), 0)
+  assert.equal(session.token!.length, 600)
+  assert.equal(clearShopPasswordReveal().token, undefined)
+})
+
+test('test_task_094_credential_reveal_invalid_input_rejected', () => {
+  // 异常输入：读取失败路径调用清空后不残留明文。
+  const session = beginShopPasswordReveal(clearShopPasswordReveal(), 7, 'pw7', 0)
+  const afterFailure = clearShopPasswordReveal()
+  assert.equal(isShopPasswordRevealActive(afterFailure, 0), false)
+  assert.equal(afterFailure.token, undefined, '失败后无明文残留')
+  assert.equal(isShopPasswordRevealActive(session, 0), true, '原会话不受影响(每次新会话)')
+})
+
+test('test_task_094_credential_reveal_dependency_failure_returns_actionable_message', () => {
+  // 依赖失败/可操作：揭示会话纯逻辑复用短时语义；不写持久化/日志。
+  const mod = readSource('src/pages/shop/shop-credential-reveal.ts')
+  assert.equal(/axios|http\.|vue|console\./.test(mod), false, '揭示会话保持纯逻辑')
+  assert.match(mod, /DEFAULT_SHOP_PASSWORD_REVEAL_MS/)
+})