迁移合同费用通用附件

1、删除旧费用附件 API、CRUD、模型和专用前端面板，统一改用通用附件能力。

2、调整合同费用接口为 study_id 语义，并补充合同、凭证、发票等附件类型的权限映射。

3、将合同费用新建和编辑改为抽屉流程，详情页与列表页复用同一编辑组件。

4、补充数据库迁移、附件列表、合同费用抽屉和权限场景测试，覆盖旧权限移除与新流程。

frontend/src/views/fees/ContractFeePermissions.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it } from "vitest";
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+
+const read = (relativePath: string) => readFileSync(resolve(__dirname, relativePath), "utf8");
+
+describe("Contract fee project permissions", () => {
+  it("hides list create/delete controls when the matching backend operation is not allowed", () => {
+    const source = read("./ContractFees.vue");
+
+    expect(source).toContain('v-if="canCreate"');
+    expect(source).toContain('v-if="canDelete"');
+    expect(source).toContain("if (!canCreate.value)");
+    expect(source).toContain("if (!canDelete.value)");
+    expect(source).not.toContain(':disabled="!canCreate"');
+    expect(source).not.toContain(':disabled="!canDelete || isInactiveSite(scope.row.center_id)"');
+  });
+
+  it("hides detail edit controls and blocks direct navigation without update permission", () => {
+    const source = read("./ContractFeeDetail.vue");
+
+    expect(source).toContain('v-if="canWrite"');
+    expect(source).toContain("if (!canWrite.value)");
+  });
+});