Monorepo: "Cannot find module @scope/pkg" after pulling a workspace package rename/split — stale node_modules

In a pnpm/Turborepo monorepo, typecheck (or build/test) suddenly fails with error TS2307: Cannot find module '@scope/new-package' or its corresponding type declarations — pointing at a package you didn't touch. The import looks correct and the referenced package exists on disk. It happens right after pulling a branch that renamed or split workspace packages (e.g. a namespace change @old/* → @new/*, or extracting packages/ai code into a new packages/embedding).