test: 测试体系全面优化，修复 Windows SQLite EBUSY 和前端产品缺陷

测试基础设施
- 统一 SQLite 测试 DB/临时目录 helper（tests/helpers.ts），支持 Windows EBUSY 重试清理
- 测试库使用 PRAGMA journal_mode=DELETE 避免 WAL 句柄延迟
- 路由 handler 测试改用 createMigratedMemoryTestDatabase 避免 File DB 锁
- SQLite 聚焦 --rerun-each=20 全部通过（720 pass）

后端测试补强
- 新增 tests/server/app.test.ts 真实 startServer 集成测试
- 覆盖 /api/meta、项目 CRUD、错误路径、静态 fallback、安全 header
- bootstrap/logger 测试捕获预期输出，消除测试噪音

前端测试补强
- 移除 .ant-* 内部类名依赖，改为角色/文本/导航/请求契约断言
- 项目页补充搜索、Tab 切换、表单、表格操作、错误反馈行为测试
- 新增 hooks（use-theme-preference、use-sidebar-collapsed、use-projects）纯逻辑测试
- 新增 ErrorBoundary 错误展示和刷新按钮测试
- 新增搜索清空行为测试
- 测试 setup 过滤 antd/rc-trigger NaN height warning

产品修复（测试暴露）
- 修复 ProjectToolbar 搜索框无法输入（新增 draftKeyword 状态）
- 加固 ProjectFormModal 表单字段同步（useEffect 替代不可靠的 afterOpenChange）
- 清理 ProjectFormModal 冗余 afterOpenChange 同步逻辑

重构与合规
- ProjectContext 拆分为三文件满足 React Fast Refresh 规则
- use-projects.ts 导出内部 helper 函数供测试验证
- scripts/build.ts 提取纯生成函数供测试使用，修复构建步骤日志编号
- 修复 build 测试覆盖真实生成逻辑

文档同步
- 更新后端/前端/开发文档测试规范、质量门禁和 helper 使用说明

tests/web/test-utils.tsx

@@ -19,10 +19,48 @@ void mock.module("recharts", () => ({
   YAxis: () => null,
 }));
 
+export interface FetchMockCall {
+  body?: BodyInit | null;
+  method: string;
+  url: string;
+}
+
 export interface RenderWithProvidersOptions {
   initialRoute?: string;
 }
 
+export function installFetchMock(handler: (call: FetchMockCall) => Promise<Response> | Response): FetchMockCall[] {
+  const calls: FetchMockCall[] = [];
+  const mocked = (async (input: RequestInfo | URL, init?: RequestInit) => {
+    const request = input instanceof Request ? input : undefined;
+    const url = request?.url ?? (typeof input === "string" ? input : input instanceof URL ? input.href : input.url);
+    const call: FetchMockCall = {
+      body: init?.body ?? null,
+      method: init?.method ?? request?.method ?? "GET",
+      url,
+    };
+    calls.push(call);
+    return handler(call);
+  }) as typeof fetch;
+
+  globalThis.fetch = mocked;
+  window.fetch = mocked;
+  return calls;
+}
+
+export function jsonResponse(body: unknown, init?: ResponseInit): Response {
+  const headers = new Headers(init?.headers);
+  if (!headers.has("Content-Type")) headers.set("Content-Type", "application/json");
+  return new Response(JSON.stringify(body), {
+    headers,
+    status: init?.status ?? 200,
+  });
+}
+
+export function mockMetaResponse(): Response {
+  return jsonResponse({ ok: true, service: "test-app", timestamp: "2024-01-01T00:00:00.000Z", version: "0.1.0" });
+}
+
 export function renderWithProviders(ui: React.ReactElement, options?: RenderWithProvidersOptions) {
   const queryClient = createTestQueryClient();
   const initialRoute = options?.initialRoute ?? "/";
@@ -58,38 +96,3 @@ function createTestQueryClient() {
     },
   });
 }
-
-// Custom test helpers (替代 jest-dom matchers)
-export const testHelpers = {
-  toBeInTheDocument: (element: Element | null) => {
-    const pass = element !== null && document.contains(element);
-    return {
-      message: () => (pass ? "Expected element not to be in document" : "Expected element to be in document"),
-      pass,
-    };
-  },
-  toHaveAttribute: (element: Element | null, attr: string, value?: string) => {
-    const pass = value === undefined ? (element?.hasAttribute(attr) ?? false) : element?.getAttribute(attr) === value;
-    return {
-      message: () =>
-        pass ? `Expected element not to have attribute "${attr}"` : `Expected element to have attribute "${attr}"`,
-      pass,
-    };
-  },
-  toHaveClass: (element: Element | null, className: string) => {
-    const pass = element?.classList.contains(className) ?? false;
-    return {
-      message: () =>
-        pass ? `Expected element not to have class "${className}"` : `Expected element to have class "${className}"`,
-      pass,
-    };
-  },
-  toHaveTextContent: (element: Element | null, text: RegExp | string) => {
-    const content = element?.textContent ?? "";
-    const pass = element !== null && (typeof text === "string" ? content.includes(text) : text.test(content));
-    return {
-      message: () => (pass ? `Expected element not to have text "${text}"` : `Expected element to have text "${text}"`),
-      pass,
-    };
-  },
-};