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)/radio/apply/page.tsx

@@ -8,7 +8,9 @@ import { auth } from "@/lib/auth";
 import { db, RadioApplications } from "@/lib/db";
 import { formatDate } from "@/lib/format-date";
 
-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;
 
 function feedbackStyle(tone: "success" | "error"): CSSProperties {
 	const accent =

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

@@ -6,7 +6,9 @@ import { ContentCard } from "@/components/public/ui";
 import { db, RadioContests } 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;
 
 export default async function RadioContestDetailPage({
 	params,

src/app/(site)/radio/contests/page.tsx

@@ -5,7 +5,9 @@ import { ContentCard, EmptyState } from "@/components/public/ui";
 import { db, RadioContests } 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;
 
 export default async function RadioContestsPage() {
 	const t = await getTranslations("pages.radioContests");

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

@@ -6,7 +6,9 @@ import { ContentCard } from "@/components/public/ui";
 import { db, RadioGiveaways } 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;
 
 export default async function RadioGiveawayDetailPage({
 	params,

src/app/(site)/radio/giveaways/page.tsx

@@ -5,7 +5,9 @@ import { ContentCard, EmptyState } from "@/components/public/ui";
 import { db, RadioGiveaways } 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;
 
 export default async function RadioGiveawaysPage() {
 	const t = await getTranslations("pages.radioGiveaways");

src/app/(site)/radio/layout.tsx

@@ -2,6 +2,10 @@ import Link from "next/link";
 import { getTranslations } from "next-intl/server";
 import type { ReactNode } from "react";
 
+// 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;
+
 const RADIO_SIDEBAR_LINKS = [
 	{ key: "schedule", href: "/radio/schedule", icon: "🗓️" },
 	{ key: "shouts", href: "/radio/shouts", icon: "📣" },

src/app/(site)/radio/leaderboard/page.tsx

@@ -6,7 +6,9 @@ import { db } from "@/lib/db";
 import { avatarImageUrl } from "@/lib/format";
 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 LeaderRow = {
 	username: string;

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

@@ -5,8 +5,11 @@ import { ContentCard, EmptyState, OnlineBadge } from "@/components/public/ui";
 import { db, RadioSchedules, User } from "@/lib/db";
 import { siteSettings } from "@/lib/services/site-settings";
 
+// 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;
+
 // Radio config + today's schedule are read live from the DB / settings table.
-export const revalidate = 300;
 
 // Canonical weekday order so today's slots come out chronologically and we can
 // match the current day against whatever casing the `day` column stores.

src/app/(site)/radio/requests/page.tsx

@@ -7,7 +7,9 @@ import { auth } from "@/lib/auth";
 import { db, RadioSongRequests, User } from "@/lib/db";
 import { formatDate } from "@/lib/format-date";
 
-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<{ posted?: string; error?: string }>;
 

src/app/(site)/radio/schedule/page.tsx

@@ -3,7 +3,9 @@ import { getTranslations } from "next-intl/server";
 import { ContentCard, EmptyState } from "@/components/public/ui";
 import { db, RadioSchedules, User } from "@/lib/db";
 
-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;
 
 // Weekly order so the table reads Monday → Sunday regardless of insert order.
 // The `day` column stores a free-form string; we key case-insensitively.

src/app/(site)/radio/shouts/page.tsx

@@ -9,7 +9,9 @@ import { avatarImageUrl } from "@/lib/format";
 import { formatDate } from "@/lib/format-date";
 import { siteSettings } from "@/lib/services/site-settings";
 
-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<{ posted?: string; error?: string }>;