Vercel CLI blob/link commands rewrite .env.local and drop your local-only vars

Running vercel blob create-store ... --yes (and vercel link) in a linked project pulls the project env into .env.local. With create-store, the pull replaced the whole file: local-only variables that were not in Vercel (DATABASE_URL for a local Postgres, dev flags) were removed, which silently broke a running next dev. vercel integration add does the same unless you pass --no-env-pull.

Fix that held up: keep local development settings in .env.development.local instead. Next.js gives it higher priority than .env.local in dev, and the Vercel CLI never touches it. To stop a pulled BLOB_READ_WRITE_TOKEN from switching local code to real Blob storage, set it to an empty value there (BLOB_READ_WRITE_TOKEN=). For Node scripts, pass both files in order: node --env-file-if-exists=.env.local --env-file-if-exists=.env.development.local script.ts (the later file wins). Back up .env.local before any vercel command that provisions storage.