Workflows not bundled on page router #143

I tried workflow on a Next.js Page Router project and ran into a couple of issues:

1. It isn't clear the missing app directory error is coming from withWorkflow: https://github.com/vercel/workflow/blob/main/packages/cli/src/lib/builders/next-build.ts#L459-L461
2. Workflows that might be referenced from API routes are not bundled (as observed in app/.well-known/workflow/v1/flow/route.js) unless the file name matches a pattern that app router uses: https://github.com/vercel/workflow/blob/main/packages/cli/src/lib/builders/next-build.ts#L324. Renaming the API route to route.ts resolves this issue.

Including the missing error incase it helps someone searching as well:

ReferenceError: Workflow "workflow//workflows/hmm.ts//handleUserSignup" must be a function, but got "undefined" instead