feat: 完成 F18 审批规则维护（API+前端）\n\n- 新增 /api/approval-rules 管理接口（system.settings）并写审计\n- 前端新增审批规则页与菜单入口（system.settings）\n- 更新 P5 蓝图 v3 中 F18 状态为 DONE

client/src/api/approvalRules.ts

@@ -0,0 +1,68 @@
+import { apiRequestData } from "./http";
+
+export type ApprovalRoleCode =
+  | "employee"
+  | "manager"
+  | "ceo"
+  | "finance"
+  | "finance_mgr"
+  | "administration"
+  | "hr"
+  | "admin";
+
+export type ApprovalRule = {
+  id: string;
+  name: string;
+  minAmount: string;
+  maxAmount: string | null;
+  level1Role: ApprovalRoleCode;
+  level2Role: ApprovalRoleCode | null;
+  level3Role: ApprovalRoleCode | null;
+  enabled: boolean;
+  priority: number;
+  createdAt: string | null;
+  updatedAt: string | null;
+};
+
+export type ApprovalRulesListResponse = {
+  enabled: boolean | null;
+  items: ApprovalRule[];
+};
+
+export async function fetchApprovalRules(params?: { enabled?: boolean }) {
+  const qs = new URLSearchParams();
+  if (params?.enabled != null) {
+    qs.set("enabled", params.enabled ? "true" : "false");
+  }
+
+  const query = qs.toString();
+  return apiRequestData<ApprovalRulesListResponse>(`/api/approval-rules${query ? `?${query}` : ""}`);
+}
+
+export type ApprovalRuleCreatePayload = {
+  name: string;
+  minAmount: string;
+  maxAmount: string | null;
+  level1Role: ApprovalRoleCode;
+  level2Role: ApprovalRoleCode | null;
+  level3Role: ApprovalRoleCode | null;
+  enabled?: boolean;
+  priority?: number;
+};
+
+export async function createApprovalRule(payload: ApprovalRuleCreatePayload) {
+  return apiRequestData<ApprovalRule>("/api/approval-rules", {
+    method: "POST",
+    body: JSON.stringify(payload),
+  });
+}
+
+export type ApprovalRulePatchPayload = Partial<ApprovalRuleCreatePayload>;
+
+export async function patchApprovalRule(approvalRuleId: string, payload: ApprovalRulePatchPayload) {
+  return apiRequestData<ApprovalRule>(`/api/approval-rules/${approvalRuleId}`, {
+    method: "PATCH",
+    body: JSON.stringify(payload),
+  });
+}
+