feat(admin): Phase 8 模型供应商管理 — provider/model CRUD + 启停 + 定价 + 设默认

后端:ModelConfig.is_default + migration;get_default_model 优先 is_default 否则回落最早 active(零回归);
adminpanel providers CRUD(api_key write-only 不回传)+ models CRUD(?provider/capability 筛)+ set-default(同 capability 清旧);
IsPlatformAdmin + 审计。
前端:adminApi providers/models/setDefault;Admin 模型供应商页(供应商表+模型表+启停+定价+设默认+供应商/模型弹窗)。
测试:adminpanel 51 单测过(api_key 隐藏+入库/CRUD/set-default 改 get_default_model);
apps.ai 仍仅 3 个进场前既有失败(零回归);无头 e2e _admin-p8.mjs 5 断言过 + 0 console error
(用一次性禁用 provider+model capability=export,无副作用,跑完删);tsc+build 绿。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/frontend/src/api.ts

@@ -1,5 +1,7 @@
 import type {
   AdminLedger,
+  AdminModel,
+  AdminProvider,
   AdminQualityWord,
   AdminQuotaPolicy,
   AdminReviewAsset,
@@ -648,5 +650,36 @@ export const adminApi = {
   },
   deleteQuotaPolicy(id: string) {
     return request<void>(`/api/admin/quota-policies/${id}/`, { method: "DELETE" });
+  },
+  providers() {
+    return request<AdminProvider[]>("/api/admin/providers/");
+  },
+  createProvider(payload: { name: string; display_name: string; base_url?: string; api_key?: string; status?: string }) {
+    return request<AdminProvider>("/api/admin/providers/", { method: "POST", body: JSON.stringify(payload) });
+  },
+  updateProvider(id: string, payload: Record<string, unknown>) {
+    return request<AdminProvider>(`/api/admin/providers/${id}/`, { method: "PATCH", body: JSON.stringify(payload) });
+  },
+  deleteProvider(id: string) {
+    return request<void>(`/api/admin/providers/${id}/`, { method: "DELETE" });
+  },
+  models(params?: { provider?: string; capability?: string }) {
+    const qs = new URLSearchParams();
+    if (params?.provider) qs.set("provider", params.provider);
+    if (params?.capability) qs.set("capability", params.capability);
+    const q = qs.toString();
+    return request<AdminModel[]>(`/api/admin/models/${q ? `?${q}` : ""}`);
+  },
+  createModel(payload: { provider: string; name: string; display_name: string; capability: string; endpoint?: string; unit_price?: string; status?: string }) {
+    return request<AdminModel>("/api/admin/models/", { method: "POST", body: JSON.stringify(payload) });
+  },
+  updateModel(id: string, payload: Record<string, unknown>) {
+    return request<AdminModel>(`/api/admin/models/${id}/`, { method: "PATCH", body: JSON.stringify(payload) });
+  },
+  deleteModel(id: string) {
+    return request<void>(`/api/admin/models/${id}/`, { method: "DELETE" });
+  },
+  setDefaultModel(id: string) {
+    return request<AdminModel>(`/api/admin/models/${id}/set-default/`, { method: "POST" });
   }
 };