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

@@ -15,10 +15,6 @@ import {
 } from "@/lib/db";
 import { formatDate } from "@/lib/format-date";
 
-// 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 }>;
 
 function feedbackStyle(tone: "success" | "error"): CSSProperties {

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

@@ -8,10 +8,6 @@ import { ContentCard } from "@/components/public/ui";
 import { auth } from "@/lib/auth";
 import { db, Guilds } from "@/lib/db";
 
-// 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 }>;
 
 function feedbackStyle(tone: "success" | "error"): CSSProperties {

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

@@ -7,10 +7,6 @@ import { ContentCard, EmptyState } from "@/components/public/ui";
 import { db, Guilds, GuildsForumsThreads, User } from "@/lib/db";
 import { formatDate } from "@/lib/format-date";
 
-// 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 }>;
 
 function feedbackStyle(tone: "success" | "error"): CSSProperties {

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

@@ -8,10 +8,6 @@ import { avatarImageUrl } from "@/lib/format";
 import { formatDate } from "@/lib/format-date";
 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;
-
 type GuildView = {
 	id: number;
 	name: string;

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

@@ -5,10 +5,6 @@ import { ContentCard, EmptyState } from "@/components/public/ui";
 import { db, Guilds } from "@/lib/db";
 import { excerpt } from "@/lib/format";
 
-// 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" };
 
 type GuildCard = {