feat: 接入模型动态 Fallback 与调用审计

core/frontend/src/admin-page.css

@@ -258,6 +258,61 @@
   overflow: auto;
 }
 .admin-json-err { color: var(--accent-crimson); background: var(--crimson-bg); border-color: var(--crimson-bd); }
+.admin-attempt-list {
+  margin: 0 0 20px;
+  background: var(--surface);
+  border: 1px solid var(--border-muted);
+  border-radius: var(--r-md);
+  overflow: hidden;
+}
+.admin-attempt {
+  padding: 14px 16px;
+}
+.admin-attempt + .admin-attempt { border-top: 1px solid var(--border-faint); }
+.admin-attempt-head {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  margin-bottom: 8px;
+}
+.admin-attempt-seq { color: var(--black-alpha-48); font-size: 11px; }
+.admin-attempt-kind { margin-left: auto; color: var(--black-alpha-56); font-size: 11px; }
+.admin-attempt-model {
+  display: flex;
+  align-items: baseline;
+  gap: 6px;
+  color: var(--accent-black);
+  font-size: 13.5px;
+  line-height: 1.5;
+}
+.admin-attempt-model strong { font-weight: 500; }
+.admin-attempt-sep { color: var(--black-alpha-24); }
+.admin-attempt-meta {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 4px 14px;
+  margin-top: 6px;
+  color: var(--black-alpha-48);
+  font-size: 11px;
+}
+.admin-attempt-error {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  margin-top: 10px;
+  padding: 8px 10px;
+  background: var(--crimson-bg);
+  border-radius: var(--r-sm);
+  color: var(--accent-crimson);
+  font-size: 12px;
+  line-height: 1.6;
+  word-break: break-word;
+}
+
+@media (max-width: 640px) {
+  .admin-attempt-head { align-items: flex-start; flex-wrap: wrap; }
+  .admin-attempt-kind { width: 100%; margin-left: 0; }
+}
 
 /* ── 计费 / 额度策略 ── */
 .admin-switch-row {

core/frontend/src/routes/admin/admin-tasks.tsx

@@ -30,6 +30,12 @@ function statusPill(status: string) {
   return <span className="pill info"><span className="dot" />进行中</span>;
 }
 
+function attemptKind(attempt: AdminTaskDetail["attempts"][number]) {
+  if (attempt.is_fallback) return "Fallback";
+  if (attempt.is_retry) return "原模型重试";
+  return "首次调用";
+}
+
 export function AdminTasksPage({ notify }: { notify: Notify }) {
   const [tasks, setTasks] = useState<AdminTask[]>([]);
   const [count, setCount] = useState(0);
@@ -171,13 +177,55 @@ export function AdminTasksPage({ notify }: { notify: Notify }) {
                 <p className="admin-modal-desc">加载中…</p>
               ) : (
                 <>
+                  {(() => {
+                    const attempts = detail.attempts || [];
+                    const finalAttempt = [...attempts].reverse().find((attempt) => attempt.status === "succeeded");
+                    const fallbackUsed = attempts.some((attempt) => attempt.is_fallback);
+                    return (
                   <div className="admin-detail-meta">
                     <div><span className="k">状态</span><span className="v">{statusPill(detail.status)}</span></div>
                     <div><span className="k">团队</span><span className="v">{detail.team_name || "—"}</span></div>
                     <div><span className="k">模型</span><span className="v">{detail.model_name || "—"}</span></div>
                     <div><span className="k">计价</span><span className="v mono">{pts(detail.estimated_cost)} → {pts(detail.actual_cost)} 积分{detail.cost_anomaly ? " ⚠" : ""}</span></div>
                     <div><span className="k">平台成本</span><span className="v mono">{Number(detail.base_cost || 0) > 0 ? `¥${detail.base_cost} · 毛利 ${detail.margin_yuan != null ? `¥${detail.margin_yuan}` : "—"}` : "未知"}</span></div>
+                    <div><span className="k">模型调用</span><span className="v mono">{attempts.length ? `${attempts.length} 次 · ${fallbackUsed ? "发生 Fallback" : "未切换"}` : "旧任务 · 无尝试链"}</span></div>
+                    {finalAttempt && <div><span className="k">最终成功模型</span><span className="v">{finalAttempt.provider_display_name || finalAttempt.provider_name} / {finalAttempt.model_display_name || finalAttempt.model_name}</span></div>}
                   </div>
+                    );
+                  })()}
+                  {detail.attempts?.length > 0 && (
+                    <>
+                      <div className="admin-detail-subhead">模型调用链 · {detail.attempts.length} 次</div>
+                      <div className="admin-attempt-list">
+                        {detail.attempts.map((attempt) => (
+                          <div className="admin-attempt" key={attempt.id}>
+                            <div className="admin-attempt-head">
+                              <span className="admin-attempt-seq mono">// {String(attempt.sequence).padStart(2, "0")}</span>
+                              {statusPill(attempt.status)}
+                              <span className="admin-attempt-kind mono">{attemptKind(attempt)}</span>
+                            </div>
+                            <div className="admin-attempt-model">
+                              <span>{attempt.provider_display_name || attempt.provider_name}</span>
+                              <span className="admin-attempt-sep">/</span>
+                              <strong>{attempt.model_display_name || attempt.model_name}</strong>
+                            </div>
+                            <div className="admin-attempt-meta mono">
+                              <span>{attempt.operation}</span>
+                              <span>{attempt.duration_ms == null ? "耗时 —" : `耗时 ${attempt.duration_ms} ms`}</span>
+                              <span>{Number(attempt.platform_cost || 0) > 0 ? `平台成本 ¥${attempt.platform_cost}` : "平台成本未知"}</span>
+                              {attempt.provider_task_id && <span>Provider ID {attempt.provider_task_id}</span>}
+                            </div>
+                            {(attempt.error_type || attempt.raw_error) && (
+                              <div className="admin-attempt-error">
+                                <span className="mono">[{attempt.error_type || "unknown"}{attempt.provider_error_code ? ` · ${attempt.provider_error_code}` : ""}]</span>
+                                <span>{attempt.raw_error || attempt.safe_error_summary}</span>
+                              </div>
+                            )}
+                          </div>
+                        ))}
+                      </div>
+                    </>
+                  )}
                   {detail.error_message && (
                     <>
                       <div className="admin-detail-subhead">错误</div>

core/frontend/src/types.ts

@@ -133,6 +133,33 @@ export type AdminTask = {
   reapable?: boolean;
   created_at: string;
 };
+export type AdminModelAttempt = {
+  id: string;
+  sequence: number;
+  provider_name: string;
+  provider_display_name: string;
+  model_name: string;
+  model_display_name: string;
+  public_model_name: string;
+  capability: string;
+  operation: string;
+  status: string;
+  is_retry: boolean;
+  is_fallback: boolean;
+  previous_attempt: string | null;
+  provider_task_id: string;
+  started_at: string;
+  finished_at: string | null;
+  duration_ms: number | null;
+  error_type: string;
+  provider_error_code: string;
+  raw_error: string;
+  safe_error_summary: string;
+  usage: Record<string, unknown>;
+  platform_cost: string;
+  request_summary: Record<string, unknown>;
+  response_summary: Record<string, unknown>;
+};
 export type AdminTaskDetail = AdminTask & {
   project: string | null;
   idempotency_key: string;
@@ -141,6 +168,7 @@ export type AdminTaskDetail = AdminTask & {
   error_message: string;
   submitted_at: string | null;
   completed_at: string | null;
+  attempts: AdminModelAttempt[];
 };
 export type AdminLedger = {
   id: string;