feat: parallelize audit repair and add nitro/SQL repair options

- Parallelize icon and nitro downloads in the audit repair with a
  sliding-window worker pool (6 concurrent) to speed up large catalogs
- Add repairMissingNitros: fetch missing .nitro bundles from configured
  nitro sources (Wibbo default), validating each bundle before writing
- Add catalog-repair service: generate/apply catalog_items SQL for furni
  missing a catalog entry and repair FurnitureData.json (add missing +
  dedupe classnames)
- Wire all options through the audit API and client UI with live progress
  and result stats (icons, nitros, SQL, furnidata)
- Add Wibbo as default nitro source alongside existing icon sources
- Ignore runtime furni assets downloaded into public/ during repair

src/lib/services/clone-sources.ts

@@ -35,6 +35,16 @@ export const DEFAULT_ICON_SOURCES: CloneSource[] = [
 	},
 ];
 
+export const DEFAULT_NITRO_SOURCES: CloneSource[] = [
+	{
+		id: "default-wibbo",
+		name: "Wibbo",
+		furnidataUrl: "",
+		nitroBaseUrl: "https://assets.wibbo.org/bundled/furniture",
+		iconBaseUrl: "",
+	},
+];
+
 export async function listSources(): Promise<CloneSource[]> {
 	const raw = (await siteSettings.get(KEY, "[]")) ?? "[]";
 	try {