feat(tenant/kol): let KOLs self-subscribe to their own published packages

Add /kol/manage/packages/:id/self-subscription POST/DELETE on the tenant
side so a KOL can grant themselves access to their own published package
without going through the marketplace approval flow. Reject self-subscribe
through the marketplace with a clear error, expose owned_by_current_tenant
on package responses, and surface a self_subscription block on KolPackage
Response. The admin-web KOL workspace gets 订阅自己 / 取消订阅 entries with
matching messaging in the marketplace detail view.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/lib/api.ts

@@ -449,6 +449,17 @@ export const kolManageApi = {
       {},
     );
   },
+  selfSubscribePackage(id: number) {
+    return apiClient.post<KolPackageSummary, Record<string, never>>(
+      `/api/tenant/kol/manage/packages/${id}/self-subscription`,
+      {},
+    );
+  },
+  cancelSelfSubscription(id: number) {
+    return apiClient.remove<KolPackageSummary>(
+      `/api/tenant/kol/manage/packages/${id}/self-subscription`,
+    );
+  },
   deletePackage(id: number) {
     return apiClient.remove<null>(`/api/tenant/kol/manage/packages/${id}`);
   },