feat(catalog): store furniture bundles as .hab instead of .nitro

Every bundle the CMS writes — upload, clone, sync, repair and the pet /
effect / figure importers — now lands as `<classname>.hab`, the extension
this deployment's renderer asks for. `.hab` and `.nitro` are the same
container, so an upload of either extension is accepted.

Resolution goes through one module, src/lib/furni/bundle-file.ts, so
nothing has to know the extension twice. Every existence check probes
`.hab` first and falls back to `.nitro`: the on-disk asset set is still
predominantly `.nitro`, and without the fallback Studio would report every
imported item as missing and the cleanup scan would classify 18k live
bundles as fake leftovers. Downloads are unchanged — Habbo's CDN and every
configured clone source still serve `.nitro`, so the conversion happens on
write, not on request.

Deliberately unchanged: the staged-attachment store in furni-attachment.ts
keys on a UUID and never reaches the client, so renaming it would break
in-flight recovery jobs.

Adds scripts/migrate-nitro-to-hab.ts to rename the existing asset set. It
refuses to run without --dry-run or --yes, never overwrites an existing
.hab, never deletes, and is idempotent.

Note: renderer-config.json lives outside this repo and was patched to
.hab separately; that file is served with a 30-day max-age, so returning
clients need a cms-client cache purge to pick the change up.

src/lib/services/repair-icons.ts

@@ -2,6 +2,7 @@ import { existsSync, promises as fs } from "node:fs";
 import os from "node:os";
 import { sql } from "drizzle-orm";
 import { queryRows } from "@/lib/db";
+import { resolveBundleInDir } from "@/lib/furni/bundle-file";
 import { logServerError } from "@/lib/server-log";
 import { extractFurniIconPng } from "@/lib/services/clone-icon";
 import {
@@ -263,13 +264,13 @@ export async function repairMissingIcons(
 			}
 		}
 
-		// 2) Extract from a local .nitro bundle (checked across every target).
+		// 2) Extract from a local bundle (checked across every target).
 		if (!ok) {
 			for (const n of names) {
 				let foundNitro = false;
 				for (const dir of nitroDirs) {
-					const nitroPath = getRuntimePath(dir, `${n}.nitro`);
-					if (!existsSync(nitroPath)) continue;
+					const nitroPath = resolveBundleInDir(dir, n);
+					if (!nitroPath) continue;
 					foundNitro = true;
 					try {
 						const nitroBuf = await fs.readFile(nitroPath);