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

src/server/checker/engine.ts

@@ -1,8 +1,9 @@
-import { groupBy, Semaphore } from "es-toolkit";
+import { groupBy, isError, Semaphore } from "es-toolkit";
 
 import type { ProbeStore } from "./store";
 import type { CheckResult, ResolvedTargetBase } from "./types";
 
+import { errorFailure } from "./expect/failure";
 import { checkerRegistry } from "./runner";
 
 const PRUNE_INTERVAL_MS = 3600000;
@@ -64,11 +65,21 @@ export class ProbeEngine {
       }),
     );
 
-    for (const result of results) {
+    for (const [index, result] of results.entries()) {
       if (result.status === "fulfilled") {
         this.writeResult(result.value);
       } else {
+        const target = targets[index];
         console.warn("探针执行失败:", result.reason);
+        if (!target) continue;
+        this.writeResult({
+          durationMs: null,
+          failure: errorFailure("internal", "engine", formatReason(result.reason)),
+          matched: false,
+          statusDetail: null,
+          targetName: target.name,
+          timestamp: new Date().toISOString(),
+        });
       }
     }
   }
@@ -106,3 +117,7 @@ export class ProbeEngine {
     });
   }
 }
+
+function formatReason(reason: unknown): string {
+  return isError(reason) ? reason.message : String(reason);
+}