refactor: 整合财务系统到主应用并重构后端架构

主要变更:
- 将独立的 web-finance 应用整合到 web-antd 主应用中
- 重命名 backend-mock 为 backend,增强后端功能
- 新增财务模块 API 端点(账户、预算、类别、交易)
- 增强财务仪表板和报表功能
- 添加 SQLite 数据存储支持和财务数据导入脚本
- 优化路由结构,删除冗余的 finance-system 模块

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/backend/api/finance/categories.post.ts

@@ -0,0 +1,23 @@
+import { readBody } from 'h3';
+
+import { createCategoryRecord } from '~/utils/finance-metadata';
+import { useResponseError, useResponseSuccess } from '~/utils/response';
+
+export default defineEventHandler(async (event) => {
+  const body = await readBody(event);
+
+  if (!body?.name || !body?.type) {
+    return useResponseError('分类名称和类型为必填项', -1);
+  }
+
+  const category = createCategoryRecord({
+    name: body.name,
+    type: body.type,
+    icon: body.icon,
+    color: body.color,
+    userId: 1,
+    isActive: body.isActive ?? true,
+  });
+
+  return useResponseSuccess(category);
+});