feat: speed up admin clone import and enable Cache Components

- Clone import: defer FurnitureData.json writes and append all entries in a
  single batched write instead of one read-modify-write per item, removing
  the main serialization bottleneck for large batches.
- Clone import: raise SSE batch concurrency cap from 5 to 10 and bump the
  clone client/route default from 2 to 6.
- Add a flush hook to runSseBatch so callers can batch deferred work before
  batch_complete is emitted, and surface flush errors as an error event.
- Enable Next.js Cache Components (instant: false opt-out) and silence the
  related build warnings in next.config.ts.
- Switch isomorphic-dompurify to dompurify and refresh dependencies.

package.json

@@ -13,10 +13,14 @@
 		"lint": "biome check .",
 		"format": "biome format --write .",
 		"test": "vitest",
+		"typecheck": "tsc --noEmit",
 		"db:generate": "drizzle-kit generate",
 		"db:migrate": "drizzle-kit migrate",
 		"db:studio": "drizzle-kit studio"
 	},
+	"lint-staged": {
+		"*.{js,ts,jsx,tsx,json}": "biome check --write --no-errors-on-unmatched"
+	},
 	"dependencies": {
 		"@base-ui/react": "1.7.0",
 		"@dnd-kit/core": "6.3.1",