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/server/db/providers.ts

@@ -1,10 +1,10 @@
 import type Database from "bun:sqlite";
 
-import { and, desc, eq, like, sql } from "drizzle-orm";
-import { drizzle } from "drizzle-orm/bun-sqlite";
+import { desc, eq, like } from "drizzle-orm";
 
 import type { CreateProviderRequest, Provider, ProviderOption, UpdateProviderRequest } from "../../shared/api";
 
+import { paginateQuery, wrap } from "./connection";
 import { providers } from "./schema";
 
 export function createProvider(
@@ -80,7 +80,6 @@ export function listProviders(
   raw: Database,
   options: { keyword?: string; page: number; pageSize: number },
 ): { items: Provider[]; page: number; pageSize: number; total: number } {
-  const db = wrap(raw);
   const conditions = [];
 
   if (options.keyword) {
@@ -88,31 +87,13 @@ export function listProviders(
     conditions.push(like(providers.name, pattern));
   }
 
-  const where = conditions.length > 0 ? and(...conditions) : undefined;
-
-  const countResult = db
-    .select({ count: sql<number>`count(*)` })
-    .from(providers)
-    .where(where)
-    .get();
-
-  const total = Number(countResult?.count ?? 0);
-
-  const rows = db
-    .select()
-    .from(providers)
-    .where(where)
-    .orderBy(desc(providers.createdAt))
-    .limit(options.pageSize)
-    .offset((options.page - 1) * options.pageSize)
-    .all();
-
-  return {
-    items: rows.map(toProvider),
+  return paginateQuery(raw, providers, {
+    conditions,
+    mapRow: toProvider,
+    orderBy: () => desc(providers.createdAt),
     page: options.page,
     pageSize: options.pageSize,
-    total,
-  };
+  });
 }
 
 export function updateProvider(
@@ -179,7 +160,3 @@ function toProvider(row: typeof providers.$inferSelect): Provider {
     updatedAt: row.updatedAt,
   };
 }
-
-function wrap(raw: Database) {
-  return drizzle(raw);
-}