R54 A1-A6：Cutover 控制台与特性开关增强

- Feature Flag 变更历史查看与影响范围预览
- Feature Flag 批量操作（启用/禁用/继承）
- Cutover 控制台页面增强（摘要卡片、时间线、延迟生效）
- 单测覆盖 changelog、batch、权限边界

client/src/api/featureFlags.ts

@@ -1,8 +1,32 @@
 import { apiRequestData } from "./http";
 
-export type FeatureFlagKey = "erp_sync" | "invoice_verification" | "leave_holiday_calendar" | "budget_precheck_v1" | "payment_batch_v1" | "portal_home_v1" | "global_search_v1" | "announcements_v1" | "workflow_definition_admin_v1" | "cutover_console_v1" | "presence_board_v1" | "weekly_report_v1" | "employee_lifecycle_v1" | "todo_board_v1" | "project_domain_v1" | "project_linking_v1" | "project_communication_log_v1" | "project_closure_checklist_v1" | "confidential_doc_refs_v1" | "public_security_hardening_v1";
+export type FeatureFlagKey =
+  | "ai_assist"
+  | "erp_sync"
+  | "invoice_verification"
+  | "leave_holiday_calendar"
+  | "budget_precheck_v1"
+  | "payment_batch_v1"
+  | "portal_home_v1"
+  | "global_search_v1"
+  | "announcements_v1"
+  | "workflow_definition_admin_v1"
+  | "cutover_console_v1"
+  | "presence_board_v1"
+  | "weekly_report_v1"
+  | "employee_lifecycle_v1"
+  | "todo_board_v1"
+  | "wecom_entry_v1"
+  | "project_domain_v1"
+  | "project_linking_v1"
+  | "project_communication_log_v1"
+  | "project_closure_checklist_v1"
+  | "confidential_doc_refs_v1"
+  | "public_security_hardening_v1";
+
 export type FeatureFlagOverrideMode = "inherit" | "force_on" | "force_off";
 export type FeatureFlagRolloutType = "global" | "department_allowlist";
+export type FeatureFlagSection = "main" | "admin" | "backup";
 
 export type FeatureFlagItem = {
   id: string | null;
@@ -23,10 +47,51 @@ export type FeatureFlagItem = {
   requiresDepartment: boolean;
 };
 
+export type FeatureFlagSnapshot = {
+  overrideMode: FeatureFlagOverrideMode;
+  rolloutType: FeatureFlagRolloutType;
+  departmentIds: string[];
+  note: string;
+  version: number;
+};
+
+export type FeatureFlagChangelogItem = {
+  id: string;
+  actorId: string;
+  actorName: string;
+  createdAt: string | null;
+  from: FeatureFlagSnapshot | null;
+  to: FeatureFlagSnapshot | null;
+};
+
+export type FeatureFlagImpactNavigationItem = {
+  label: string;
+  path: string;
+  section: FeatureFlagSection;
+};
+
+export type FeatureFlagImpactBackendModule = {
+  label: string;
+  routes: string[];
+};
+
 export type FeatureFlagListResponse = {
   items: FeatureFlagItem[];
 };
 
+export type FeatureFlagChangelogResponse = {
+  page: number;
+  pageSize: number;
+  total: number;
+  items: FeatureFlagChangelogItem[];
+};
+
+export type FeatureFlagImpactResponse = {
+  flagKey: FeatureFlagKey;
+  navigationItems: FeatureFlagImpactNavigationItem[];
+  backendModules: FeatureFlagImpactBackendModule[];
+};
+
 export type FeatureFlagUpdatePayload = {
   overrideMode: FeatureFlagOverrideMode;
   rolloutType: FeatureFlagRolloutType;
@@ -35,13 +100,50 @@ export type FeatureFlagUpdatePayload = {
   expectedVersion: number;
 };
 
+export type FeatureFlagBatchUpdatePayload = {
+  items: Array<{
+    flagKey: FeatureFlagKey;
+    overrideMode: FeatureFlagOverrideMode;
+    expectedVersion: number;
+  }>;
+  note: string;
+};
+
 export async function fetchFeatureFlags() {
   return apiRequestData<FeatureFlagListResponse>("/api/system/feature-flags");
 }
 
+export async function fetchFeatureFlagChangelog(
+  flagKey: FeatureFlagKey,
+  params?: { page?: number; pageSize?: number },
+) {
+  const searchParams = new URLSearchParams();
+  if (params?.page) {
+    searchParams.set("page", String(params.page));
+  }
+  if (params?.pageSize) {
+    searchParams.set("pageSize", String(params.pageSize));
+  }
+  const suffix = searchParams.toString() ? `?${searchParams.toString()}` : "";
+  return apiRequestData<FeatureFlagChangelogResponse>(
+    `/api/system/feature-flags/${flagKey}/changelog${suffix}`,
+  );
+}
+
+export async function fetchFeatureFlagImpact(flagKey: FeatureFlagKey) {
+  return apiRequestData<FeatureFlagImpactResponse>(`/api/system/feature-flags/${flagKey}/impact`);
+}
+
 export async function updateFeatureFlag(flagKey: FeatureFlagKey, payload: FeatureFlagUpdatePayload) {
   return apiRequestData<{ item: FeatureFlagItem }>(`/api/system/feature-flags/${flagKey}`, {
     method: "PUT",
     body: JSON.stringify(payload),
   });
 }
+
+export async function batchUpdateFeatureFlags(payload: FeatureFlagBatchUpdatePayload) {
+  return apiRequestData<{ count: number }>("/api/system/feature-flags/batch", {
+    method: "POST",
+    body: JSON.stringify(payload),
+  });
+}