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

src/server/checker/engine.ts

@@ -5,17 +5,21 @@ import type { CheckResult, ResolvedTargetBase } from "./types";
 
 import { checkerRegistry } from "./runner";
 
+const PRUNE_INTERVAL_MS = 3600000;
+
 export class ProbeEngine {
+  private retentionMs: number;
   private semaphore: Semaphore;
   private store: ProbeStore;
   private targetNameToId = new Map<string, number>();
   private targets: ResolvedTargetBase[];
   private timers: Array<ReturnType<typeof setInterval>> = [];
 
-  constructor(store: ProbeStore, targets: ResolvedTargetBase[], maxConcurrentChecks?: number) {
+  constructor(store: ProbeStore, targets: ResolvedTargetBase[], maxConcurrentChecks?: number, retentionMs?: number) {
     this.store = store;
     this.targets = targets;
     this.semaphore = new Semaphore(maxConcurrentChecks ?? 20);
+    this.retentionMs = retentionMs ?? 0;
     this.refreshCache();
   }
 
@@ -31,6 +35,14 @@ export class ProbeEngine {
 
       this.timers.push(timer);
     }
+
+    if (this.retentionMs > 0) {
+      this.store.prune(this.retentionMs);
+      const pruneTimer = setInterval(() => {
+        this.store.prune(this.retentionMs);
+      }, PRUNE_INTERVAL_MS);
+      this.timers.push(pruneTimer);
+    }
   }
 
   stop(): void {