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/admin/moderation/actions/page.tsx

@@ -2,6 +2,10 @@ import { redirect } from "next/navigation";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { ModActionsClient } from "./mod-actions-client";
 
+// 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 QuickActionsPage() {
 	const { session, permissions } = await getAdminContext();
 	if (!canAccess(permissions, PERMS.MODERATION_EDIT, session.user.rank))

src/app/admin/moderation/cfh/[id]/page.tsx

@@ -4,6 +4,10 @@ import { Ban, db, SupportTickets, User } from "@/lib/db";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { CfhDetail } from "./cfh-detail";
 
+// 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 CfhDetailPage({
 	params,
 }: {

src/app/admin/moderation/cfh/page.tsx

@@ -17,6 +17,10 @@ import { formatDate } from "@/lib/format-date";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { type CfhRow, CfhTable } from "./cfh-table";
 
+// 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 CfhListPage({
 	searchParams,
 }: {

src/app/admin/moderation/page.tsx

@@ -17,6 +17,10 @@ import { getMinStaffRank } from "@/lib/admin/min-staff-rank";
 import { AdminAuditLog, Ban, db, SupportTickets, User } from "@/lib/db";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 
+// 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 CFH_STATES: Record<number, { label: string; class: string }> = {
 	0: {
 		label: "Open",

src/app/admin/moderation/team/page.tsx

@@ -14,6 +14,10 @@ import {
 } from "@/lib/db";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 
+// 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 ModTeamPage() {
 	const { session, permissions } = await getAdminContext();
 	if (!canAccess(permissions, PERMS.MODERATION_VIEW, session.user.rank))