feat(可视化前端): 接入执行视图和任务详情 API

保留运行列表读取，同时新增按 script_build_id 获取完整 ExecutionView、按 task_id 获取 TaskDetail 的客户端函数，为动态选择与详情面板提供真实数据入口。

visualization/frontend/lib/api.ts

@@ -1,4 +1,4 @@
-import type { RunGraph, RunSummary } from "@/lib/types";
+import type { ExecutionView, RunSummary, TaskDetail } from "@/lib/types";
 
 const API_BASE = process.env.NEXT_PUBLIC_API_BASE ?? "http://127.0.0.1:8788";
 
@@ -12,6 +12,10 @@ export function fetchRuns(signal?: AbortSignal) {
   return getJson<RunSummary[]>("/api/runs", signal);
 }
 
-export function fetchGraph(scriptBuildId: number, signal?: AbortSignal) {
-  return getJson<RunGraph>(`/api/runs/${scriptBuildId}/graph`, signal);
+export function fetchExecution(scriptBuildId: number, signal?: AbortSignal) {
+  return getJson<ExecutionView>(`/api/runs/${scriptBuildId}/execution`, signal);
+}
+
+export function fetchTaskDetail(scriptBuildId: number, taskId: string, signal?: AbortSignal) {
+  return getJson<TaskDetail>(`/api/runs/${scriptBuildId}/tasks/${taskId}`, signal);
 }