refactor: 前端架构重构 — hook拆分、组件拆分、类型筛选器动态化、Meta API

- 后端新增 GET /api/meta 端点（checkerRegistry.supportedTypes）及 MetaResponse 类型
- 前端 hook 拆分为 use-queries.ts（全局查询+useMeta）和 use-target-detail.ts（Drawer状态）
- TargetDetailDrawer 拆分为 OverviewTab + HistoryTab + history-table-columns + stats.ts
- 类型筛选器由 meta API 动态驱动，删除 target-type-display 静态映射
- 列定义改为工厂函数 createTargetTableColumns(checkerTypes)，TargetGroup 新增 columns prop
- 修复 StatusDonut key、StatusBar maxSlots prop、TrendChart 移除 loading prop
- 补充 utils/time、utils/stats、动态列工厂测试，删除旧 mapping 测试
- 同步 delta specs 到主 specs，归档 frontend-architecture-refactor change

src/server/app.ts

@@ -5,6 +5,7 @@ import { createApiError, jsonResponse } from "./helpers";
 import { guardGetHead } from "./middleware";
 import { handleHealth } from "./routes/health";
 import { handleHistory } from "./routes/history";
+import { handleMeta } from "./routes/meta";
 import { handleSummary } from "./routes/summary";
 import { handleTargets } from "./routes/targets";
 import { handleTrend } from "./routes/trend";
@@ -29,6 +30,10 @@ export function createFetchHandler(options: AppOptions) {
       return handleHealth(request.method, options.mode);
     }
 
+    if (url.pathname === "/api/meta") {
+      return handleMetaRoute(request, options.mode);
+    }
+
     if (url.pathname.startsWith("/api/") && options.store) {
       return handleApiRoute(url, request, options.store, options.mode);
     }
@@ -78,3 +83,9 @@ function handleApiRoute(url: URL, request: Request, store: ProbeStore, mode: Run
 
   return jsonResponse(createApiError("API route not found", 404), { method, mode, status: 404 });
 }
+
+function handleMetaRoute(request: Request, mode: RuntimeMode): Response {
+  const guardResult = guardGetHead(request.method, mode);
+  if (guardResult) return guardResult;
+  return handleMeta(request.method, mode);
+}

src/server/routes/meta.ts

@@ -0,0 +1,12 @@
+import type { MetaResponse, RuntimeMode } from "../../shared/api";
+
+import { checkerRegistry } from "../checker/runner";
+import { jsonResponse } from "../helpers";
+
+export function handleMeta(method: string, mode: RuntimeMode): Response {
+  const response: MetaResponse = {
+    checkerTypes: checkerRegistry.supportedTypes,
+  };
+
+  return jsonResponse(response, { method, mode });
+}