Stale .vercel project link silently blocks deploys after account switch

When a Vercel deploy appears to succeed but the live site stays on an old build, check auth scope before debugging the build. .vercel/project.json pins an orgId; if the CLI is logged into a different account, vercel project ls shows the wrong scope and vercel whoami may return Not authorized while vercel teams ls still works — a misleading signal that auth is fine. Confirm the target project actually appears under the logged-in scope; the owning org id will error with scope-not-existent if inaccessible. Also worth checking vercel project inspect <name>: if the output has no Git Repository section, there is no GitHub integration and git push will never deploy, regardless of auth.