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/catalog-git-snapshot.ts

@@ -37,6 +37,10 @@ const CONFIG_FILES = [
 	"ProductData.json",
 ];
 const TABLES = ["items_base", "catalog_pages", "catalog_items"] as const;
+// The catalog export must ship both bundle extensions for every asset type:
+// `.hab` is what imports write now (furniture, pets, effects and figures all
+// go through it), `.nitro` is what the existing asset set is made of.
+const BUNDLE_FILE_RE = /\.(?:nitro|hab)$/i;
 const identifier = (name: string) => `\`${name.replaceAll("`", "``")}\``;
 
 export async function createCatalogSnapshot(
@@ -75,13 +79,13 @@ export async function createCatalogSnapshot(
 	await addTree(
 		path.join(getPublicAssetRoot(), "public/nitro-assets/bundled"),
 		"Gamedata/bundled",
-		/\.nitro$/i,
+		BUNDLE_FILE_RE,
 	);
 	if (gamedata) {
 		await addTree(
 			path.join(gamedata, "bundled"),
 			"Gamedata/bundled",
-			/\.nitro$/i,
+			BUNDLE_FILE_RE,
 		);
 		await addTree(
 			path.join(gamedata, "icons"),
@@ -94,18 +98,18 @@ export async function createCatalogSnapshot(
 			/\.(png|gif|webp|jpe?g)$/i,
 		);
 	}
-	await addTree(furni.nitroDir, "Gamedata/bundled/furniture", /\.nitro$/i);
+	await addTree(furni.nitroDir, "Gamedata/bundled/furniture", BUNDLE_FILE_RE);
 	await addTree(furni.iconDir, "Gamedata/icons", /\.(png|gif|webp|jpe?g)$/i);
 	for (const type of ["figure", "effect"]) {
 		const configured = await siteSettings.get(`${type}_nitro_dir`, "");
 		if (configured?.trim())
-			await addTree(configured, `Gamedata/bundled/${type}`, /\.nitro$/i);
+			await addTree(configured, `Gamedata/bundled/${type}`, BUNDLE_FILE_RE);
 	}
 	// Pets currently write directly to the CMS directory.
 	await addTree(
 		path.join(getPublicAssetRoot(), "public/nitro-assets/bundled/pet"),
 		"Gamedata/bundled/pet",
-		/\.nitro$/i,
+		BUNDLE_FILE_RE,
 	);
 	const configRoot = gamedata
 		? path.join(gamedata, "config")