feat: harden atoms-nexst against review findings (37 items)

Second review pass covering security, performance, admin tooling and the
public/room flows. All HIGH and MEDIUM findings from the audit are resolved;
nothing in this commit changes the visible feature set.

Authentication & session security
- CSP is now set on the request headers in the proxy, which is what Next.js
  uses to derive the render nonce, so the nonce is effective.
- 2FA: an already-enabled user cannot re-enroll, the setup endpoint is
  rate-limited per account, and confirmed codes are persisted so the second
  secret no longer silently never applies.
- Password reset revokes the ticket, authTicket and all personal access
  tokens, and bumps the token version so existing sessions die. The same
  revocation is now wired into the staff-side password reset.
- /reset and /verify return a stable error code instead of raw text; the
  mail lookups are ordered by id so duplicates cannot vary between runs.
- Resending the verification mail gets a per-address cooldown on top of the
  per-user limit.
- Issue API tokens with the narrower radio/ticket ability set instead of "*".

Authorization & input handling
- Mid-rank staff can no longer keep dynamically granted non-view admin.*
  permissions: existing grants are revoked by migration and the grant lookup
  is restricted to "%.view". Rank guards use the dynamic super-admin check.
- Alerting a user is permission-checked and audited like the other tools.
- Material mutations (giveCredits/giveDuckets/giveDiamonds, the admin user
  actions route, bulk user actions) are capped and rank-guarded, and bulk
  ids are bounded.
- updateRoom / updateRoomItem write through a field allowlist, and items
  may only be edited through their own room.
- Classnames reaching the filesystem are validated before use so a crafted
  value cannot escape the asset directories.
- The word filter now also covers offline mails, guild forum threads and
  replies, and user mottos.
- Media uploads are validated by magic bytes, /api/media requires the page
  edit permission, APP_URL must be configured once mail is enabled, and the
  diagnostics error route checks the fetch site header.

Admin tooling
- Secret settings render masked and cannot be overwritten with a blank or
  an arbitrary raw key; radio credentials are new password inputs.
- Commandocentrum balance changes are audited.
- Admin list pagination reads the caller's per-page instead of the max, and
  the log exporter caps offset and search length.

Performance
- Catalog translations are cached per module, with a cheap revision hash;
  the public online count uses a stale window instead of hammering the DB.
- The cache warmup now primes the payload the home route actually reads.
- TopHeader batches its queries into one round trip, and LCP avatars load
  eagerly.
- motion/react and sonner are no longer part of the root layout; the nav
  dropdown and mobile nav panels are lazy client chunks. Anonymous visitors
  again get the navigation chrome, and public pages get an edge cacheable
  response.

Accessibility
- Nested <main> elements in phase pages became <section>; the page entrance
  and route progress animations are pure CSS that respect reduced motion.

src/lib/services/furni-import.ts

@@ -4,6 +4,7 @@ import path from "node:path";
 import { promisify } from "node:util";
 import { and, eq, type SQL, sql } from "drizzle-orm";
 import { CatalogPages, db, execResult, ItemsBase, queryRows } from "@/lib/db";
+import { isSafeAssetName } from "@/lib/furni/classname";
 import { offerPurchasabilityProblems } from "@/lib/furni/offer-purchasability";
 import { officialHabboEnrichmentWarning } from "@/lib/habbo-gamedata-hotel";
 import { logger } from "@/lib/logger";
@@ -599,7 +600,6 @@ export async function importSingleFurni(params: {
 }): Promise<ImportSingleResult> {
 	const {
 		id: originalId,
-		classname,
 		name,
 		description,
 		type,
@@ -615,6 +615,16 @@ export async function importSingleFurni(params: {
 	} = params;
 	const warnings: string[] = [];
 
+	// A classname becomes a file name below (swf/nitro/icon). It travels from a
+	// request body into `path.join`, so it must never be able to contain a path
+	// separator — otherwise a crafted value escapes the asset directories.
+	const classname = params.classname.trim();
+	if (!isSafeAssetName(classname)) {
+		throw new Error(
+			`Invalid furniture classname: ${JSON.stringify(params.classname)}`,
+		);
+	}
+
 	// Check if already exists by classname OR by spriteId (primary key collision).
 	const [existsByName] = await db
 		.select({