feat: 完成应收款管理模块

后端：
- 创建 Receivable 实体类（应收款编号、需求ID、项目ID、客户ID、金额、状态、逾期天数）
- 创建 ReceivableMapper 接口
- 创建 ReceivableService 业务逻辑层
  - 分页查询、保存/更新应收款
  - 自动计算未收款金额和逾期天数
  - 记录收款并自动更新状态
- 创建 ReceivableController 控制器（RESTful API）

前端：
- 创建 receivable.js API 文件（7个接口）

应收款管理模块核心功能完成！✅

fund-admin/src/api/receivable.js

@@ -0,0 +1,76 @@
+import request from '../utils/request'
+
+/**
+ * 获取应收款列表（分页）
+ */
+export const getReceivableList = (params) => {
+  return request({
+    url: '/proj/api/v1/receivable/list',
+    method: 'get',
+    params
+  })
+}
+
+/**
+ * 获取应收款详情
+ */
+export const getReceivableById = (receivableId) => {
+  return request({
+    url: `/proj/api/v1/receivable/${receivableId}`,
+    method: 'get'
+  })
+}
+
+/**
+ * 创建应收款
+ */
+export const createReceivable = (data) => {
+  return request({
+    url: '/proj/api/v1/receivable',
+    method: 'post',
+    data
+  })
+}
+
+/**
+ * 更新应收款
+ */
+export const updateReceivable = (receivableId, data) => {
+  return request({
+    url: `/proj/api/v1/receivable/${receivableId}`,
+    method: 'put',
+    data
+  })
+}
+
+/**
+ * 删除应收款
+ */
+export const deleteReceivable = (receivableId) => {
+  return request({
+    url: `/proj/api/v1/receivable/${receivableId}`,
+    method: 'delete'
+  })
+}
+
+/**
+ * 记录收款
+ */
+export const recordPayment = (receivableId, amount) => {
+  return request({
+    url: `/proj/api/v1/receivable/${receivableId}/payment`,
+    method: 'post',
+    params: { amount }
+  })
+}
+
+/**
+ * 更新应收款状态
+ */
+export const updateReceivableStatus = (receivableId, status) => {
+  return request({
+    url: `/proj/api/v1/receivable/${receivableId}/status`,
+    method: 'put',
+    params: { status }
+  })
+}

fundplatform

@@ -1 +1 @@
-Subproject commit 743d7038c11151d9e405f8a99f750ba48b143a17
+Subproject commit 91ba1879f285919f8c9d01f74e2a5c6a1842511e