feat: 基础设施加固 — 修复构建、数据保留、错误边界、bundle 拆分

- 修复 build script 引用已删除的 registerCheckers，恢复生产构建
- 生产入口添加 SIGINT/SIGTERM 优雅关闭（与 dev.ts 一致）
- 新增 runtime.retention 配置（默认 7d），ProbeStore.prune() 定时清理过期数据
- parseDuration 扩展支持 h/d 单位
- 新增前端 ErrorBoundary 组件，防止渲染错误白屏
- Vite codeSplitting.groups 拆分 vendor chunks（业务代码 1180KB → 47KB）
- 同步 delta specs 到主规范

scripts/build.ts

@@ -112,21 +112,26 @@ import { ProbeStore } from "../src/server/checker/store";
 import { ProbeEngine } from "../src/server/checker/engine";
 import { startServer } from "../src/server/server";
 import { readRuntimeConfig } from "../src/server/config";
-import { registerCheckers } from "../src/server/checker/runner";
 import { staticAssets } from "./static-assets";
 
 async function main() {
-  registerCheckers();
-
   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);
+  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",