feat: 配置变量系统与 target id/name 双字段标识

- 新增顶层 variables 段支持 string/number/boolean 字面量
- target 字符串字段支持 、、{...} 转义语法
- 变量解析优先级: variables -> process.env -> 默认值 -> 报错
- 完整引用保留原始类型，部分引用拼接为字符串
- 变量替换在 YAML 解析后、AJV 校验前执行
- 替换仅作用于 targets，跳过 id/type 字段
- target 新增必填 id 字段作为唯一标识，name 改为可选展示名称
- 数据库存储/API/前端全面迁移到 id 标识
- 统一 checker 运行时类型检查为 es-toolkit predicates
- 同步 delta specs 到主 specs，归档 config-variables 变更

src/web/hooks/use-queries.ts

@@ -5,7 +5,7 @@ import type { DashboardResponse, MetaResponse, TargetMetricsResponse } from "../
 const queryKeys = {
   dashboard: () => ["dashboard", "24h", 30] as const,
   meta: () => ["meta"] as const,
-  metrics: (targetId: number, from: string, to: string, bucket: "1h") =>
+  metrics: (targetId: string, from: string, to: string, bucket: "1h") =>
     ["metrics", targetId, from, to, bucket] as const,
 };
 
@@ -32,7 +32,7 @@ export function useMeta() {
   });
 }
 
-export function useTargetMetrics(targetId: null | number, from: string, to: string, bucket: "1h") {
+export function useTargetMetrics(targetId: null | string, from: string, to: string, bucket: "1h") {
   return useQuery({
     enabled: targetId !== null && !!from && !!to,
     queryFn: () => {

src/web/hooks/use-target-detail.ts

@@ -7,11 +7,11 @@ import { subtractHours } from "../utils/time";
 import { fetchJson, useDashboard, useTargetMetrics } from "./use-queries";
 
 const detailQueryKeys = {
-  history: (targetId: number, from: string, to: string, page: number) => ["history", targetId, from, to, page] as const,
+  history: (targetId: string, from: string, to: string, page: number) => ["history", targetId, from, to, page] as const,
 };
 
 export function useTargetDetail() {
-  const [selectedTargetId, setSelectedTargetId] = useState<null | number>(null);
+  const [selectedTargetId, setSelectedTargetId] = useState<null | string>(null);
   const [timeFrom, setTimeFrom] = useState("");
   const [timeTo, setTimeTo] = useState("");
   const [historyPage, setHistoryPage] = useState(1);