refactor: 后端架构加固 — 泛型化、批量查询、bootstrap 统一、路径修复与 pageSize 上限

- CheckerDefinition 泛型化，HTTP/Command checker 移除 resolved target 断言
- 新增 ProbeStore.getAllRecentSamples 消除 targets 路由 N+1 查询
- 统一 getAllTargetStats 与 getTargetStats 的 availability 精度
- Engine rejected 结果写入 internal error 记录，提升可观测性
- 新增 bootstrap.ts 统一 dev/production 启动序列
- dataDir 相对路径改为基于配置文件目录解析
- validatePagination 增加 pageSize 上限 200 校验
- 修复 ErrorBoundary override 标记
- 更新 README/DEVELOPMENT 文档，新增完整测试覆盖

scripts/build.ts

@@ -107,37 +107,13 @@ ${assetEntries.join("\n")}
 async function writeGeneratedEntry() {
   await writeFile(
     generatedEntryPath,
-    `import { loadConfig } from "../src/server/checker/config-loader";
-import { ProbeStore } from "../src/server/checker/store";
-import { ProbeEngine } from "../src/server/checker/engine";
-import { startServer } from "../src/server/server";
+    `import { bootstrap } from "../src/server/bootstrap";
 import { readRuntimeConfig } from "../src/server/config";
 import { staticAssets } from "./static-assets";
 
 async function main() {
   const { configPath } = readRuntimeConfig();
-  const config = await loadConfig(configPath);
-
-  const store = new ProbeStore(config.dataDir + "/probe.db");
-  store.syncTargets(config.targets);
-
-  const engine = new ProbeEngine(store, config.targets, config.maxConcurrentChecks, config.retentionMs);
-  engine.start();
-
-  const shutdown = () => {
-    engine.stop();
-    store.close();
-    process.exit(0);
-  };
-  process.on("SIGINT", shutdown);
-  process.on("SIGTERM", shutdown);
-
-  startServer({
-    config: { host: config.host, port: config.port },
-    mode: "production",
-    staticAssets,
-    store,
-  });
+  await bootstrap({ configPath, mode: "production", staticAssets });
 }
 
 void main().catch((error) => {