feat(roundtable): 会商诊断日志 + 后台挂起卡死兜底(idle 超时)

- 新增会商全流程诊断日志：新表 roundtable_diagnostics + 仓储 + admin API
  (/api/roundtable-diagnostics) + 管理员诊断页(会商页右上角设置按钮入口)，
  覆盖第一/二/三步及后台执行器/进程内网关各处报错与关键事件，支持按
  范围/阶段/级别/事件/关键词筛选 + 分页。诊断写入全程 best-effort，绝不打断会商。
- 修复后台挂起「执行完第一个席位后永久卡死」：进程内网关每轮 agent run 改为
  idle(无活动)超时(默认 20min)——只要还在持续产出 token/工具事件就一直等，
  仅当连续无任何输出才判卡死并取消+报错+落 seat_turn_timeout 诊断；慢但活着的
  生成绝不打断。可经 ROUNDTABLE_SEAT_IDLE_TIMEOUT_SECONDS 调整。
- 一并提交进行中的会商 seat-skill 注入 / 业务链条编辑器相关改动。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend-web/src/strategy-components/api/roundtable-diagnostics.ts

@@ -0,0 +1,131 @@
+/**
+ * 圆桌会商诊断日志（管理员）API 客户端 + React Query hooks。
+ *
+ * 后端：`/api/roundtable-diagnostics`（见 app/gateway/routers/roundtable_diagnostics.py）。
+ * 全部 admin-gated。snake_case ⇄ camelCase 在此边界收敛。
+ */
+
+import { useQuery } from "@tanstack/react-query";
+
+import { apiFetch } from "@/core/api/fetch-client";
+import { getBackendBaseURL } from "@/core/config";
+
+const BASE = () => `${getBackendBaseURL()}/api/roundtable-diagnostics`;
+
+export interface DiagnosticItem {
+  id: string;
+  scope: string;
+  stage: string;
+  level: string;
+  event: string;
+  message: string | null;
+  detail: unknown;
+  jobId: string | null;
+  draftId: string | null;
+  taskId: string | null;
+  userId: string | null;
+  agentId: string | null;
+  agentName: string | null;
+  cycle: number | null;
+  createdAt: string | null;
+}
+
+export interface DiagnosticListResponse {
+  items: DiagnosticItem[];
+  total: number;
+  limit: number;
+  offset: number;
+}
+
+export interface DiagnosticFacets {
+  scope: string[];
+  stage: string[];
+  level: string[];
+  event: string[];
+}
+
+export interface DiagnosticFilters {
+  scope?: string;
+  stage?: string;
+  level?: string;
+  event?: string;
+  jobId?: string;
+  draftId?: string;
+  taskId?: string;
+  userId?: string;
+  q?: string;
+  since?: string;
+  until?: string;
+  limit?: number;
+  offset?: number;
+}
+
+async function readJson<T>(res: Response, ctx: string): Promise<T> {
+  if (!res.ok) {
+    const data = await res.json().catch(() => null as unknown);
+    const detail =
+      data && typeof data === "object" && "detail" in data
+        ? String((data as { detail: unknown }).detail)
+        : `${ctx} failed (${res.status})`;
+    throw new Error(detail);
+  }
+  return (await res.json()) as T;
+}
+
+function buildQuery(f: DiagnosticFilters): string {
+  const p = new URLSearchParams();
+  const map: Record<string, string | number | undefined> = {
+    scope: f.scope,
+    stage: f.stage,
+    level: f.level,
+    event: f.event,
+    job_id: f.jobId,
+    draft_id: f.draftId,
+    task_id: f.taskId,
+    user_id: f.userId,
+    q: f.q,
+    since: f.since,
+    until: f.until,
+    limit: f.limit,
+    offset: f.offset,
+  };
+  for (const [k, v] of Object.entries(map)) {
+    if (v !== undefined && v !== null && String(v).length > 0) p.set(k, String(v));
+  }
+  const qs = p.toString();
+  return qs ? `?${qs}` : "";
+}
+
+export async function listDiagnostics(f: DiagnosticFilters): Promise<DiagnosticListResponse> {
+  const res = await apiFetch(`${BASE()}${buildQuery(f)}`, { method: "GET" });
+  return readJson<DiagnosticListResponse>(res, "list diagnostics");
+}
+
+export async function getDiagnosticFacets(): Promise<DiagnosticFacets> {
+  const res = await apiFetch(`${BASE()}/facets`, { method: "GET" });
+  return readJson<DiagnosticFacets>(res, "diagnostic facets");
+}
+
+// ── React Query hooks ──────────────────────────────────────────────────────
+
+const KEY = "roundtable-diagnostics";
+
+export function useRoundtableDiagnostics(filters: DiagnosticFilters, enabled = true) {
+  return useQuery({
+    queryKey: [KEY, filters],
+    queryFn: () => listDiagnostics(filters),
+    enabled,
+    refetchOnWindowFocus: false,
+    staleTime: 10_000,
+  });
+}
+
+export function useRoundtableDiagnosticFacets(enabled = true) {
+  return useQuery({
+    queryKey: [KEY, "facets"],
+    queryFn: getDiagnosticFacets,
+    enabled,
+    refetchOnWindowFocus: false,
+    staleTime: 60_000,
+  });
+}