feat: speed up admin clone import and enable Cache Components

- Clone import: defer FurnitureData.json writes and append all entries in a
  single batched write instead of one read-modify-write per item, removing
  the main serialization bottleneck for large batches.
- Clone import: raise SSE batch concurrency cap from 5 to 10 and bump the
  clone client/route default from 2 to 6.
- Add a flush hook to runSseBatch so callers can batch deferred work before
  batch_complete is emitted, and surface flush errors as an error event.
- Enable Next.js Cache Components (instant: false opt-out) and silence the
  related build warnings in next.config.ts.
- Switch isomorphic-dompurify to dompurify and refresh dependencies.

src/app/(site)/guilds/[id]/forum/[threadId]/page.tsx

@@ -15,7 +15,9 @@ import {
 } from "@/lib/db";
 import { formatDate } from "@/lib/format-date";
 
-export const revalidate = 60;
+// TODO: Cache Components adoption. Refactor this route so this opt-out can be removed.
+// See: https://nextjs.org/docs/app/guides/migrating-to-cache-components
+export const instant = false;
 
 type SearchParams = Promise<{ replied?: string; error?: string }>;
 

src/app/(site)/guilds/[id]/forum/new/page.tsx

@@ -8,7 +8,9 @@ import { ContentCard } from "@/components/public/ui";
 import { auth } from "@/lib/auth";
 import { db, Guilds } from "@/lib/db";
 
-export const dynamic = "force-dynamic";
+// TODO: Cache Components adoption. Refactor this route so this opt-out can be removed.
+// See: https://nextjs.org/docs/app/guides/migrating-to-cache-components
+export const instant = false;
 
 type SearchParams = Promise<{ error?: string }>;
 

src/app/(site)/guilds/[id]/forum/page.tsx

@@ -7,7 +7,9 @@ import { ContentCard, EmptyState } from "@/components/public/ui";
 import { db, Guilds, GuildsForumsThreads, User } from "@/lib/db";
 import { formatDate } from "@/lib/format-date";
 
-export const revalidate = 300;
+// TODO: Cache Components adoption. Refactor this route so this opt-out can be removed.
+// See: https://nextjs.org/docs/app/guides/migrating-to-cache-components
+export const instant = false;
 
 type SearchParams = Promise<{ posted?: string }>;
 

src/app/(site)/guilds/[id]/page.tsx

@@ -8,7 +8,9 @@ import { avatarImageUrl } from "@/lib/format";
 import { formatDate } from "@/lib/format-date";
 import { siteSettings } from "@/lib/services/site-settings";
 
-export const revalidate = 300;
+// TODO: Cache Components adoption. Refactor this route so this opt-out can be removed.
+// See: https://nextjs.org/docs/app/guides/migrating-to-cache-components
+export const instant = false;
 
 type GuildView = {
 	id: number;

src/app/(site)/guilds/page.tsx

@@ -5,7 +5,9 @@ import { ContentCard, EmptyState } from "@/components/public/ui";
 import { db, Guilds } from "@/lib/db";
 import { excerpt } from "@/lib/format";
 
-export const revalidate = 300;
+// TODO: Cache Components adoption. Refactor this route so this opt-out can be removed.
+// See: https://nextjs.org/docs/app/guides/migrating-to-cache-components
+export const instant = false;
 
 export const metadata = { title: "Guilds" };