fix(admin): redirect to edit page after creating blog post

Root cause: after successful creation the form stayed on /blog/new.
User couldn't tell it worked, clicked Save again, the second attempt
hit the unique slug constraint and showed an error — making it look
like creation was broken.

Fix: adminPost is now typed, onSuccess redirects to /blog/{id} on new
posts so the user lands on the edit page immediately.

Also fixes commentCount being undefined in the list (MapPost now
includes comment count via eager-loaded Comments).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/admin/src/components/admin/admin-website-screens.tsx

@@ -3,6 +3,7 @@
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { useTranslations } from "next-intl";
 import { useEffect, useState } from "react";
+import { useRouter } from "@/i18n/routing";
 import { adminDelete, adminGet, adminPatch, adminPost, adminPut } from "@/lib/api/admin-client";
 import type {
   AdminBlogPost,
@@ -155,6 +156,7 @@ interface PostEditorProps {
 export function AdminBlogEditorScreen({ postId }: PostEditorProps) {
   const t = useTranslations("admin.website");
   const qc = useQueryClient();
+  const router = useRouter();
   const isNew = !postId;
 
   const { data: post } = useQuery({
@@ -204,11 +206,15 @@ export function AdminBlogEditorScreen({ postId }: PostEditorProps) {
   const saveMut = useMutation({
     mutationFn: () =>
       isNew
-        ? adminPost("/api/admin/website/posts", form)
-        : adminPut(`/api/admin/website/posts/${postId}`, form),
-    onSuccess: () => {
+        ? adminPost<{ id: string }>("/api/admin/website/posts", form)
+        : adminPut<{ id: string }>(`/api/admin/website/posts/${postId}`, form),
+    onSuccess: (result) => {
       qc.invalidateQueries({ queryKey: ["admin", "website", "blog"] });
       notify.success(t("saved"));
+      // After creating a new post, go to its edit page so the user can
+      // continue editing and won't accidentally hit Save again (which would
+      // fail on the unique slug constraint).
+      if (isNew) router.push(`/admin/website/blog/${result.id}`);
     },
     onError: () => notify.error(t("errorGeneric")),
   });