perf: migrate pages to Cache Components via root layout opt-out

Remove the per-route 'export const instant = false' opt-outs now that the root layout carries the single Cache Components opt-out. Child pages inherit the opt-out, so admin/mod/radio leaf pages that only access cached or DB data stay instant while runtime-dependent pages remain dynamic. Update the staff-smoke contract test to assert the root-layout contract.

src/app/admin/rooms/[id]/furni/page.tsx

@@ -6,10 +6,6 @@ import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { loadRoom } from "../../_lib/load-room";
 import { FurniClient } from "./furni-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 RoomFurniPage({
 	params,
 }: {

src/app/admin/rooms/[id]/page.tsx

@@ -1,9 +1,5 @@
 import { redirect } from "next/navigation";
 
-// 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 RoomLegacyPage({
 	params,
 }: {

src/app/admin/rooms/edit/[id]/page.tsx

@@ -8,10 +8,6 @@ import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { loadRoom } from "../../_lib/load-room";
 import { RoomEditForm } from "../../[id]/room-edit-form";
 
-// 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 RoomEditPage({
 	params,
 }: {

src/app/admin/rooms/page.tsx

@@ -7,10 +7,6 @@ import { db, Rooms } from "@/lib/db";
 import { canAccess, PERMS } from "@/lib/permissions";
 import { RoomsTable } from "./rooms-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 RoomsPage({
 	params: paramsPromise,
 	searchParams,

src/app/admin/rooms/show/[id]/page.tsx

@@ -8,10 +8,6 @@ import { Card, CardContent } from "@/components/ui/card";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { loadRoom } from "../../_lib/load-room";
 
-// 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 stateVariants: Record<
 	string,
 	"default" | "secondary" | "destructive" | "outline"