refactor: 代码审查修复 — 错误边界、DRY抽取、测试修复、合规性改进

- P1: server.ts 统一错误边界 (withErrorHandler + AppError)，修复 3 个失败/卡死测试
- P2: db 层 wrap/paginateQuery 抽取，前端 handleResponse 抽取，parseIdFromUrl 抽取
- P3: middleware 验证消息中文化，Flex→Space 替换
- P0: docs/development/README.md 新增已知设计决策章节
- P3-11 setup 拆分已尝试回退（@testing-library/react preload 依赖无法拆分）
- P3-13 config 层测试从本次变更移除

src/web/hooks/use-providers.ts

@@ -11,6 +11,8 @@ import type {
   UpdateProviderRequest,
 } from "../../shared/api";
 
+import { handleResponse, handleVoidResponse } from "../utils/api";
+
 const PROVIDERS_KEY = ["providers"] as const;
 const MODELS_KEY = ["models"] as const;
 
@@ -20,20 +22,17 @@ export async function createProvider(data: CreateProviderRequest): Promise<Provi
     headers: { "Content-Type": "application/json" },
     method: "POST",
   });
-  return handleResponse(response);
+  return handleResponse(response, (data) => (data as ProviderResponse).provider);
 }
 
 export async function deleteProvider(id: string): Promise<void> {
   const response = await fetch(`/api/providers/${id}`, { method: "DELETE" });
-  if (!response.ok) {
-    const body = (await response.json().catch(() => null)) as null | { error?: string };
-    throw new Error(body?.error ?? `HTTP ${response.status}`);
-  }
+  return handleVoidResponse(response);
 }
 
 export async function fetchProvider(id: string): Promise<Provider> {
   const response = await fetch(`/api/providers/${id}`);
-  return handleResponse(response);
+  return handleResponse(response, (data) => (data as ProviderResponse).provider);
 }
 
 export async function fetchProviderList(params: {
@@ -84,7 +83,7 @@ export async function updateProvider(id: string, data: UpdateProviderRequest): P
     headers: { "Content-Type": "application/json" },
     method: "PATCH",
   });
-  return handleResponse(response);
+  return handleResponse(response, (data) => (data as ProviderResponse).provider);
 }
 
 export function useCreateProvider() {
@@ -145,12 +144,3 @@ export function useUpdateProvider() {
     },
   });
 }
-
-async function handleResponse(response: Response): Promise<Provider> {
-  if (!response.ok) {
-    const body = (await response.json().catch(() => null)) as null | { error?: string };
-    throw new Error(body?.error ?? `HTTP ${response.status}`);
-  }
-  const data = (await response.json()) as ProviderResponse;
-  return data.provider;
-}